New Member Here - A few theories

[Chekhov MacGuffin]

Why he would put such development in a character like Okiya just to make him become Akai?

Because Aoyama Gosho is developing Akai's character through Okiya similar to how Vermouth's character was developed during her time as Ariade. So far we have only seen the business side of Akai. As Okiya, we see more of his offwork side.

Even before Vermouth became Araide she was developing like during the first episode she was introduced in, and before we even saw her as Araide or knew she was in disguise, she was given off as herself in most scenes...

And when Vermouth took off her mask, there was still an "Araide-Sensei character" around. But when Akai takes off his mask, will there be no more Okiya?

When Vermouth removed her mask, did Vermouth's Araide die?

[soratothamax]

Why he would put such development in a character like Okiya just to make him become Akai?

Because Aoyama Gosho is developing Akai's character through Okiya similar to how Vermouth's character was developed during her time as Ariade. So far we have only seen the business side of Akai. As Okiya, we see more of his offwork side.

Even before Vermouth became Araide she was developing like during the first episode she was introduced in, and before we even saw her as Araide or knew she was in disguise, she was given off as herself in most scenes...

And when Vermouth took off her mask, there was still an "Araide-Sensei character" around. But when Akai takes off his mask, will there be no more Okiya?

When Vermouth removed her mask, did Vermouth's Araide die?

yes it did. But the actual character, Araide-sensei didn't die. I don't see Okiya the same as Akai. I like Okiya the character, but I see him differently from Akai. If akai reveals, the whole character of Okiya would die if the theory that Okiya is Akai is true.

[Abs.]

Why he would put such development in a character like Okiya just to make him become Akai?

Because Aoyama Gosho is developing Akai's character through Okiya similar to how Vermouth's character was developed during her time as Ariade. So far we have only seen the business side of Akai. As Okiya, we see more of his offwork side.

Even before Vermouth became Araide she was developing like during the first episode she was introduced in, and before we even saw her as Araide or knew she was in disguise, she was given off as herself in most scenes...

And when Vermouth took off her mask, there was still an "Araide-Sensei character" around. But when Akai takes off his mask, will there be no more Okiya?

When Vermouth removed her mask, did Vermouth's Araide die?

yes it did. But the actual character, Araide-sensei didn't die. I don't see Okiya the same as Akai. I like Okiya the character, but I see him differently from Akai. If akai reveals, the whole character of Okiya would die if the theory that Okiya is Akai is true.

After Vermouth was revealed to have disguised as Araide-sensei, there was a whole case dedicated to making the reader/viewer's impression of Vermouth change - to have the reader doubt whether Vermouth is really the evil person she was made out to be previously, given the new information regarding her activities and personality while being Araide.

Similarly, if Okiya is revealed to be Akai, the reader/viewer's idea of Akai would change to accept that Akai really is someone who would hide in plain sight, water plants, and cook.

Now, throughout this whole conversation over the two threads, I've had the most trouble with the description of Okiya as "smiley" - he's nothing of the sort and I got no idea where you're getting this from.  I'd venture to say that there are more scenes of Akai smiling than of Okiya smiling.  I wouldn't call either of their smiles "smiley" ones either...  More similar to "I know something you don't" smiles...

[soratothamax]

Why he would put such development in a character like Okiya just to make him become Akai?

Because Aoyama Gosho is developing Akai's character through Okiya similar to how Vermouth's character was developed during her time as Ariade. So far we have only seen the business side of Akai. As Okiya, we see more of his offwork side.

Even before Vermouth became Araide she was developing like during the first episode she was introduced in, and before we even saw her as Araide or knew she was in disguise, she was given off as herself in most scenes...

And when Vermouth took off her mask, there was still an "Araide-Sensei character" around. But when Akai takes off his mask, will there be no more Okiya?

When Vermouth removed her mask, did Vermouth's Araide die?

yes it did. But the actual character, Araide-sensei didn't die. I don't see Okiya the same as Akai. I like Okiya the character, but I see him differently from Akai. If akai reveals, the whole character of Okiya would die if the theory that Okiya is Akai is true.

After Vermouth was revealed to have disguised as Araide-sensei, there was a whole case dedicated to making the reader/viewer's impression of Vermouth change - to have the reader doubt whether Vermouth is really the evil person she was made out to be previously, given the new information regarding her activities and personality while being Araide.

Similarly, if Okiya is revealed to be Akai, the reader/viewer's idea of Akai would change to accept that Akai really is someone who would hide in plain sight, water plants, and cook.

Now, throughout this whole conversation over the two threads, I've had the most trouble with the description of Okiya as "smiley" - he's nothing of the sort and I got no idea where you're getting this from.  I'd venture to say that there are more scenes of Akai smiling than of Okiya smiling.  I wouldn't call either of their smiles "smiley" ones either...  More similar to "I know something you don't" smiles...

Still, Araide-sensei is his own character. I don't see Vermouth differently. I did see she changed slightly, but I still think she'd kill Sherry in a heartbeat. She kills who she wants to kill.....

Okiya is the one who cooks.....Akai is the intense character who is distraught over the death of Akemi....

I think that Okiya has good deduction skills like Akai, but I can't see him the same. If they end up being the same person, the character of Okiya would disappear......and I like him as a character.

And then the face of Akai will be cooking, talking about Sherlock Holmes, drinking Bourbon, and squinting....or not....but it would be weird to see Akai doing those things that Okiya's character has been developed to do...

Different from Akai's character has been developed to be like. Akai seems to be non-stop in pursuit of the BO to get revenge. He doesn't seem like he would relax easy. And he seems like he's equal to Gin, and would go toe-to-toe with Gin in a minute. But Okiya seems more reserved and less aggressive. He seems to fight when he has to, but not come out of the shadows to do so. Also, Akai's smokes....did he all of a sudden stop when he became Okiya? Could Conan smell smoke on him or something? Okiya never seems like he lit a cigarette...

AND YES, these are my interpretations of the characters, but it's one reason why it's hard for me to see it clearly. Because I see the characters differently.

I also don't understand, if he was in disguise, how in the bathroom when Ran kicked him, he still had his mask on? He had his mask on when he was brushing his teeth? Taking a shower? hmmm....that's odd to me.

With Vermouth, she didn't have her mask on every screenshot she showed up in. When Araide showed up, it was her, but often even while she was dressed as Araide, her own face would show up to the audience, as if she still lived her life as Chris....even as Araide-sensei....if that makes sense.

She was delivered during that saga as Sometimes she was Araide-sensei, sometimes she was herself...

I don't know....often Gosho makes evidence point to one character, and makes that character out to be similar to another character....and then they end up being two different people....

Like Jodie-sensei when she had similar traits as Vermouth: she was blonde, she spoke English, and she said the same saying "a secret makes a woman woman". But she turned out to be a totally different person, who was in pursuit of Vermouth, and knew some things about Vermouth to impersonate as her. She even kept pictures of everybody in her bathroom mirror....which would make her seem like Vermouth.

To me, it seems the clues are leading you down a goose-trap, trying to make it seem like Okiya is somehow related, getting everyone's hopes up that Akai has returned as this guy, who is so equal to Akai in everything, that he could be him....

When really, he's not.

[Chekhov MacGuffin]

I also don't understand, if he was in disguise, how in the bathroom when Ran kicked him, he still had his mask on? He had his mask on when he was brushing his teeth? Taking a shower? hmmm....that's odd to me.

Red link in the signature, first paragraph under "Suggestive evidence."

With Vermouth, she didn't have her mask on every screenshot she showed up in. When Araide showed up, it was her, but often even while she was dressed as Araide, her own face would show up to the audience, as if she still lived her life as Chris....even as Araide-sensei....if that makes sense.

Someone with Akai's face is wandering around already: scar Akai. It wouldn't make sense for Gosho to spoil the arc by prematurely showing the real Akai and thus ruining the mystery of whether Akai really died.

I don't know....often Gosho makes evidence point to one character, and makes that character out to be similar to another character....and then they end up being two different people....

Like Jodie-sensei when she had similar traits as Vermouth: she was blonde, she spoke English, and she said the same saying "a secret makes a woman woman". But she turned out to be a totally different person, who was in pursuit of Vermouth, and knew some things about Vermouth to impersonate as her. She even kept pictures of everybody in her bathroom mirror....which would make her seem like Vermouth.

Kind of like how Okiya is being built up to be Bourbon? You asked for that one. ^.^

[soratothamax]

Red link in the signature, first paragraph under "Suggestive evidence."

Then why didn't his wig fly off?

Someone with Akai's face is wandering around already: scar Akai. It wouldn't make sense for Gosho to spoil the arc by prematurely showing the real Akai and thus ruining the mystery of whether Akai really died

If the "Okiya is Akai" theory is true, that is sad for me. Okiya is a character that has been progressively developed as a character, so to just "kill" that character would be a loss for me....as i like him differently from Akai....and like him for being different. It really would not be the same if he were to take off a mask and it would be Akai behind it.....

Maybe Okiya is really behind the mask of Scar Akai, and Akai is behind the mask of Okiya? But then where's Bourbon? One of the 3 isn't existing right now....

It will either be Okiya, Akai, or Bourbon. One of the characters are going to either have to "die", have already died, or doesn't exist yet as a character in order for this to work.

To me, Gosho is leading the evidence to a trap of deception....

I don't think Gosho is spoiling the arc because I don't think Akai is revealing at all, but lurking in the shadows somewhere....someone has to be. Cuz I can't see him developing a character just to throw it away as a "disguise", especially a character as important as Okiya has become in the lives of certain people.

Kind of like how Okiya is being built up to be Bourbon? You asked for that one. ^.^

We don't know who Bourbon is...so as far as we know, he is not a character that exists yet. He has not been developed.

To me, it seems that they're pointing more to Okiya being Akai than Bourbon. As you said, he drinks Bourbon like Akai did, so where is Gosho leading us down to us thinking he's Bourbon, when most of the evidence "ironically" points to Akai? Gosho knows that's what the people hope for, and is going to get people's hopes up for it. When neither scar Akai or Okiya are Akai, and Akai is probably in the shadows....

I'm not saying it's true he's in the shadows, but judging how often Akai comes out of nowhere....he very well could be.

Jodie Sensei was built up to be a character we were FAMILIAR with already, which was Vermouth. Bourbon is not a character we know. So I think the Okiya x Akai thing is most similar to the Vermouth x Jodie thing, because is built up to be a character we are familiar with as well....

[xGinx]

And what if the disguise is Akai and the true face is Okiya?? anyone thought about that?

[Chekhov MacGuffin]

Red link in the signature, first paragraph under "Suggestive evidence."

Then why didn't his wig fly off?

As I said in aforementioned paragraph, it could be his REAL HAIR, dyed and straightened. Vermouth's wig didn't fall off when Conan ruffled his hair to make him look like Takagi in Sato's love bet case. Wigs in DC seem to stick down well.  

Spoiler:

Jodie Sensei was built up to be a character we were FAMILIAR with already, which was Vermouth. Bourbon is not a character we know. So I think the Okiya x Akai thing is most similar to the Vermouth x Jodie thing, because is built up to be a character we are familiar with as well....

Incorrect. Vermouth appeared in one case before Jodie appeared although there might be a one panel cameo somewhere in between where nothing important happened (I don't remember). I hardly call that familiar. It is probably a good idea for you to reread the manga for the relevant sections before you post because so far you have posted several incorrect points based on misconceptions that wouldn't have existed if you checked first before posting.

Also saying Okiya has been built up to be Akai more than Bourbon is asinine. Here are some of the sidebars at the end of the chapters:
624: "Is Subaru with the Organization? What on Earth is Conan planning?"
640: "Okiya enjoys drinking Bourbon. Is it a coincidence!? Or..." (note this chapter came out a while before we found out Akai likes Bourbon)
666: "Haibara feels the stormy atmosphere of the men in black. So it's Subaru after all!?"
702: "Akai is discovered by Subaru, revealing a bold smile. Has this situation turned bad?"
704: "So Okiya has been looking for Akai after all!?"

[Kor]

Red link in the signature, first paragraph under "Suggestive evidence."

Then why didn't his wig fly off?

As I said in aforementioned paragraph, it could be his REAL HAIR, dyed and straightened. Vermouth's wig didn't fall off when Conan ruffled his hair to make him look like Takagi in Sato's love bet case. Wigs in DC seem to stick down well. 

Spoiler:

Jodie Sensei was built up to be a character we were FAMILIAR with already, which was Vermouth. Bourbon is not a character we know. So I think the Okiya x Akai thing is most similar to the Vermouth x Jodie thing, because is built up to be a character we are familiar with as well....

Incorrect. Vermouth appeared in one case before Jodie appeared although there might be a one panel cameo somewhere in between where nothing important happened (I don't remember). I hardly call that familiar. It is probably a good idea for you to reread the manga for the relevant sections before you post because so far you have posted several incorrect points based on misconceptions that wouldn't have existed if you checked first before posting.

Also saying Okiya has been built up to be Akai more than Bourbon is asinine. Here are some of the sidebars at the end of the chapters:
624: "Is Subaru with the Organization? What on Earth is Conan planning?"
640: "Okiya enjoys drinking Bourbon. Is it a coincidence!? Or..." (note this chapter came out a while before we found out Akai likes Bourbon)
666: "Haibara feels the stormy atmosphere of the men in black. So it's Subaru after all!?"
702: "Akai is discovered by Subaru, revealing a bold smile. Has this situation turned bad?"
704: "So Okiya has been looking for Akai after all!?"

Just to add, in other DC forums which I visited, most users think that Okiya is Bourbon only based on these ideas:
Okiya drinks Bourbon
Okiya's favorite color is black
Okiya has good deduction skills
Okiya gives Ai the "B.O." feeling

Maybe in Japan, Gosho managed to get people tricked again with the "Jodie/Vermouth" trick. Or as I said, he's out of ideas. Or, he saw how good the Vermouth twist was, that he decided to use it again.
There are many possibilities for why Gosho can be repeating the same trick.

[Abs.]

There are many possibilities for why Gosho can be repeating the same trick.

For example, the Teleportation case.

[soratothamax]

As I said in aforementioned paragraph, it could be his REAL HAIR, dyed and straightened. Vermouth's wig didn't fall off when Conan ruffled his hair to make him look like Takagi in Sato's love bet case. Wigs in DC seem to stick down well.  

Spoiler:

Takagi's wig was disheveled. And when someone puts their hand over a wig, it doesn't do anything. But when someone knocks you in the face, that wig will either move lop-sided or come off.

Come on, you really think Akai died his hair a pink color? That's just hilarious to me! I find it totally out-of-character. lol

Incorrect. Vermouth appeared in one case before Jodie appeared although there might be a one panel cameo somewhere in between where nothing important happened (I don't remember). I hardly call that familiar. It is probably a good idea for you to reread the manga for the relevant sections before you post because so far you have posted several incorrect points based on misconceptions that wouldn't have existed if you checked first before posting.

Also saying Okiya has been built up to be Akai more than Bourbon is asinine. Here are some of the sidebars at the end of the chapters:
624: "Is Subaru with the Organization? What on Earth is Conan planning?"
640: "Okiya enjoys drinking Bourbon. Is it a coincidence!? Or..." (note this chapter came out a while before we found out Akai likes Bourbon)
666: "Haibara feels the stormy atmosphere of the men in black. So it's Subaru after all!?"
702: "Akai is discovered by Subaru, revealing a bold smile. Has this situation turned bad?"
704: "So Okiya has been looking for Akai after all!?"

[/quote]

Actually, you are wrong about that. Vermouth appeared in the Meeting with the Black Organization case, where Ai turned into Shiho. From that moment, her character was developing, WAY before Jodie even showed up. That is "familiar" as we were expecting to get answers to the particular character that was being shown. she was introduced to us.

Bourbon has yet to be "revealed" or "introduced" to us in our eyes. Only Okiya and Akai. We are expecting to get answers to those characters. With bourbon, we are not quite sure how he would appear yet, so that leaves the audience not particularly expecting his character to show up as soon as much as Akai. Gosho doesn't seem to be creating Okiya up just to be Akai.

I can't imagine Okiya not existing anymore...because that is what will happen if Akai reveals. Do you really think Akai is the type of character to be behind the mask of Okiya?

That's like Gin dressing up as Vermouth....it is just hilarious! And if it is revealed that way, I will rofl!

I have read my manga, dude. I feel that Gosho is leading someone down a goosetrap. All these fans want so badly Akai to be alive that they are willing to see akai in just about any character that appears similar.

Seeing is believing. And until I see it with my own eyes, i can't believe it.

And even then, I'll LAUGH SO HARD.

[Chekhov MacGuffin]

Takagi's wig was disheveled. And when someone puts their hand over a wig, it doesn't do anything. But when someone knocks you in the face, that wig will either move lop-sided or come off.

Come on, you really think Akai died his hair a pink color?

Conan ruffled the wig, not just put his hand over it. Hattori's Kudo wig didn't come off when he removed the disguise over top of it either. Takagi put his wig over his real hair which decreases the amount of friction and makes it easier to slip. Hattori and Vermouth had their real hair pressed down with some sort of  thin-disguise-cap-cover-thing, which will increase the friction and help keep the wig on.
And who says Okiya dyes his hair pink? Okiya's hair color was decided by the animators without any colored pages to reference. For all we know Okiya has Haibara's, Sonoko's, or Eri's hair color. It probably isn't actually pink, since hair colors in DC tend to be realistic. None of the characters have commented on the pinkness which they definitely would have if it was actually dyed pink. The real explanation for why Okiya's hair has a pink tinge probably has to do with the recent anime style; the animators have been adding tones of other colors to the natural hair colors to provide some variation. The blind woman from the Gari case in 523 has cranberry hair, one of the suspects from the Iron Tanuki case (527) and the culprit from Azuha's case (526) had blue toned hair, and in the Fuurinkazan case (516) one of the victim's hair was tinted green, another's purple, and even Kazuha had a violet tinge as well.

Incorrect. Vermouth appeared in one case before Jodie appeared although there might be a one panel cameo somewhere in between where nothing important happened (I don't remember). I hardly call that familiar.

Actually, you are wrong about that. Vermouth appeared in the Meeting with the Black Organization case, where Ai turned into Shiho. From that moment, her character was developing, WAY before Jodie even showed up. That is "familiar" as we were expecting to get answers to the particular character that was being shown. she was introduced to us.

No, I'm not wrong, the Pisco case was the one case I was referring to in my previous post. Vermouth had basically no character development in that case- simply her introduction. Don't confuse the two. From that chapter alone we had very little idea of what Vermouth's personality was like except that she was maybe a mysterious person. The situation with Bourbon is the same, only we haven't seem him without a disguise yet.

Bourbon has yet to be "revealed" or "introduced" to us in our eyes. Only Okiya and Akai. We are expecting to get answers to those characters. With bourbon, we are not quite sure how he would appear yet, so that leaves the audience not particularly expecting his character to show up as soon as much as Akai. Gosho doesn't seem to be creating Okiya up just to be Akai.

I can't imagine Okiya not existing anymore...

Okiya's character will fold its development into Akai. The disguise doesn't die per say, it just adds to what we know about the other character and survives that way. Akai may not use Okiya's mannerisms and such, but what he did as Okiya will stay associated with him regardless.

Later Edit: It seems like one of soratothamax's major assertions is that she doesn't think Akai is the kind of character who would disguise himself; however, even if Akai didn't want to disguise and pretend to be more cordial than he normally is, Akai HAD to do it whether he liked it or not.
   If Akai is Okiya, then his plan must have been to fake his death while keeping it a secret from even the FBI in a "fool your friends to fool your enemies" fashion - similar to how Akai planned with Camel to return Rena to the Org. If Akai simply planned to keep on the low down away from the action, then a disguise would be sufficient and he wouldn't need to pretend to have a different personality, but this isn't the case. Akai as Okiya chose to stay where there is a high risk that he will come into contact or be observed by people who knew him previously. These people include Haibara, Jodie, Ran, and probably most importantly - Vermouth.
   Although Vermouth said she would give up on chasing Haibara, Akai wasn't party to that exchange between Conan and the actress. For all Akai knows, Vermouth is regrouping and is waiting to strike again. If Vermouth notices Akai's disguise then Kir is in major trouble. To avoid Kir's and potentially his own death, Akai has a very strong reason to act convincingly different from his usual self around everyone because who knows who Vermouth may be impersonating? Regarding Ai, she won't report Akai to the FBI or the Org, but Akai has stated he is unwilling to face her yet, so he probably isn't ready to let his identity slip to her. As for Jodie, she is a friend of Conan's and because of that there is a chance she may come into contact with Okiya if he stays close to Ai and Conan. Akai seems to think that there is a risk to letting the FBI know he is still alive, otherwise he wouldn't have hidden his plan from his fellow agents. Perhaps he thinks that the FBI agents couldn't convincingly pretend he was dead and the org might notice. The Org seems to be watching the FBI closely- they knew Camel was involved in a case and scar Akai (who is likely Bourbon) was able to track down Jodie and Camel. Vermouth and scar Akai both seem to have/be judging if there was a trick in Akai's death by observing the reactions of agents who were close to Akai, so the secrecy seems to have been a good call on Akai's part. Finally, Ran has only met Akai briefly, but unlike Jodie or Ai, she doesn't know that he is supposed to be dead and it's possible she may say something at an imprudent time or get suspicious and start investigating like when she found pictures behind Jodie's bathroom mirror.
   Additionally, if Conan stumbles across another Syndicate case and accidentally picks up heat like he did during FBI vs. the Org or someone recognizes that suspicious incidents are centered around Beika and Haido wards (like Gin did), then Okiya - who was living somewhat near to Ai and Conan before, but now is right next door to Ai- is at an increased risk of being noticed. It's all the more reason for Akai to act and appear different.
   There even has already been an even more extreme case of someone who didn't want to disguise themselves but did it anyway: Vodka at the Off-season Halloween party. Although he was ordered to wear a costume, Vodka explicitly stated the whole thing was ridiculous. He sucked it up and did it anyway.

Spoiler:

Heck, even Gin isn't above disguises. He and Vodka apparently use one to leave the lockers after the footsteps of darkness case.

Spoiler:

In summary, Akai has plenty of reasons to take on a completely different personality while in disguise even if he doesn't want to or doesn't seem like the type in order to ensure Kir's and his own safety because Akai chose to be around people who may recognize him and blow his cover if he doesn't do a convincing job.

[soratothamax]

Conan ruffled the wig, not just put his hand over it. Hattori's Kudo wig didn't come off when he removed the disguise over top of it either. Takagi put his wig over his real hair which decreases the amount of friction and makes it easier to slip. Hattori and Vermouth had their real hair pressed down with some sort of  thin-disguise-cap-cover-thing, which will increase the friction and help keep the wig on.
And who says Okiya dyes his hair pink? Okiya's hair color was decided by the animators without any colored pages to reference. For all we know Okiya has Haibara's, Sonoko's, or Eri's hair color. It probably isn't actually pink, since hair colors in DC tend to be realistic. None of the characters have commented on the pinkness which they definitely would have if it was actually dyed pink. The real explanation for why Okiya's hair has a pink tinge probably has to do with the recent anime style; the animators have been adding tones of other colors to the natural hair colors to provide some variation. The blind woman from the Gari case in 523 has cranberry hair, one of the suspects from the Iron Tanuki case (527) and the culprit from Azuha's case (526) had blue toned hair, and in the Fuurinkazan case (516) one of the victim's hair was tinted green, another's purple, and even Kazuha had a violet tinge as well.

The hair color of Okiya is also on the cover of the mangas.....the manga covers have color....

And Okiya's hair was pink....

None of those other characters got knocked in the face to the point their heads flew back....even with a secure hair net, and similar wig color to original hair, that thing wouldn't stay on with that kind of blow to the face.

Okiya's character will fold its development into Akai. The disguise doesn't die per say, it just adds to what we know about the other character and survives that way. Akai may not use Okiya's mannerisms and such, but what he did as Okiya will stay associated with him regardless.

Later Edit: It seems like one of soratothamax's major assertions is that she doesn't think Akai is the kind of character who would disguise himself; however, even if Akai didn't want to disguise and pretend to be more cordial than he normally is, Akai HAD to do it whether he liked it or not.
   If Akai is Okiya, then his plan must have been to fake his death while keeping it a secret from even the FBI in a "fool your friends to fool your enemies" fashion - similar to how Akai planned with Camel to return Rena to the Org. If Akai simply planned to keep on the low down away from the action, then a disguise would be sufficient and he wouldn't need to pretend to have a different personality, but this isn't the case. Akai as Okiya chose to stay where there is a high risk that he will come into contact or be observed by people who knew him previously. These people include Haibara, Jodie, Ran, and probably most importantly - Vermouth.
   Although Vermouth said she would give up on chasing Haibara, Akai wasn't party to that exchange between Conan and the actress. For all Akai knows, Vermouth is regrouping and is waiting to strike again. If Vermouth notices Akai's disguise then Kir is in major trouble. To avoid Kir's and potentially his own death, Akai has a very strong reason to act convincingly different from his usual self around everyone because who knows who Vermouth may be impersonating? Regarding Ai, she won't report Akai to the FBI or the Org, but Akai has stated he is unwilling to face her yet, so he probably isn't ready to let his identity slip to her. As for Jodie, she is a friend of Conan's and because of that there is a chance she may come into contact with Okiya if he stays close to Ai and Conan. Akai seems to think that there is a risk to letting the FBI know he is still alive, otherwise he wouldn't have hidden his plan from his fellow agents. Perhaps he thinks that the FBI agents couldn't convincingly pretend he was dead and the org might notice. The Org seems to be watching the FBI closely- they knew Camel was involved in a case and scar Akai (who is likely Bourbon) was able to track down Jodie and Camel. Vermouth and scar Akai both seem to have/be judging if there was a trick in Akai's death by observing the reactions of agents who were close to Akai, so the secrecy seems to have been a good call on Akai's part. Finally, Ran has only met Akai briefly, but unlike Jodie or Ai, she doesn't know that he is supposed to be dead and it's possible she may say something at an imprudent time or get suspicious and start investigating like when she found pictures behind Jodie's bathroom mirror.
   Additionally, if Conan stumbles across another Syndicate case and accidentally picks up heat like he did during FBI vs. the Org or someone recognizes that suspicious incidents are centered around Beika and Haido wards (like Gin did), then Okiya - who was living somewhat near to Ai and Conan before, but now is right next door to Ai- is at an increased risk of being noticed. It's all the more reason for Akai to act and appear different.
   There even has already been an even more extreme case of someone who didn't want to disguise themselves but did it anyway: Vodka at the Off-season Halloween party. Although he was ordered to wear a costume, Vodka explicitly stated the whole thing was ridiculous. He sucked it up and did it anyway.

Spoiler:

Heck, even Gin isn't above disguises. He and Vodka apparently use one to leave the lockers after the footsteps of darkness case.

Spoiler:

In summary, Akai has plenty of reasons to take on a completely different personality while in disguise even if he doesn't want to or doesn't seem like the type in order to ensure Kir's and his own safety because Akai chose to be around people who may recognize him and blow his cover if he doesn't do a convincing job.

A character begins their development the moment they are introduced as characters. BEGIN IT. Bourbon was only introduced as a "potential" character, who has not been introduced at all besides his name and line of work. Vermouth left the audience in speculation of her existence....Vermouth was introduced as a recognizable BO character from the moment she was introduced. Then it continued to develop from there. But we knew to expect her face in the near future. We know to expect Akai's face in the near future as well. We don't to see Bourbon's face again in the future because we've never seen it.

I understand why akai would want to be in disguise, but I can't see him being in disguise as progressively developing  character, like Okiya, who seems so different from Akai to me.

What I have underlined in bold is my main concern with this theory. If Akai is going to fold into Okiya, or vise versa, one of the character qualities will be lost. you have named "mannerisms" which is basically what I like about Okiya separate from Akai. I feel that Okiya is a uniquely developed character from many characters who have claimed to like the color "black" because: he doesn't act like the world is going to end, he isn't particularly intense, and he does things like cook and water plants, some very domestic skills. Akai....well, he is a guy on the verge of getting his rival and enemy Gin....that same guy cooking and watering plants? That is really funny.

I can see Gin dressing in disguise too, but not his whole face, and not as someone like Okiya. Maybe a wig and sunglasses that will come off in the same episode....then again, Gin isn't that type either. Hiding behind a mask shows you are in fear...and what does Gin have to fear? Except the cops, which he can avoid just by being quiet like he did in several other episodes...

[Chekhov MacGuffin]

The hair color of Okiya is also on the cover of the mangas.....the manga covers have color....
And Okiya's hair was pink....
None of those other characters got knocked in the face to the point their heads flew back....even with a secure hair net, and similar wig color to original hair, that thing wouldn't stay on with that kind of blow to the face.

I'm afraid I'll have to see the cover to believe it. I quickly flipped through a couple recent covers and didn't see one which had a colored drawing of Okiya done by Gosho on it. (Note that sometimes the anime animators' art can appear on the covers in color!) As I said before, the easiest way to explain why Ran's kick didn't knock Okiya's wig off is that Akai straightened his hair and dyed it.
The rest of the argument below doesn't relate to whether Okiya is Akai, but I'll respond to it anyway.

A character begins their development the moment they are introduced as characters. BEGIN IT. Bourbon was only introduced as a "potential" character, who has not been introduced at all besides his name and line of work.

The flaw in this argument is that you are assuming that a character must have shown their true face for the "character development" to begin. Although someone may wonder if Bourbon is a real agent or a trap for Kir, that shouldn't stop them from simultaneously thinking about what Bourbon would be like should he be real.
Even though we haven't seen Bourbon's true face, we have accumulated a bit of info about Bourbon's personality and motives through what Gin and Vodka have said about him: he is secretive like Vermouth, he likes to move on his own, Gin doesn't get along with him, he despises Akai, he doesn't think Akai is dead despite the evidence, and for some reason thinks he is the only one who is able to kill Akai. As for Vermouth, your original argument was that she was "familiar" by the time Jodie appeared. I don't really care how you want to semantically define when character development begins, but it's pretty much unarguable that there was little information about Vermouth's character when Jodie appeared.

Vermouth left the audience in speculation of her existence....Vermouth was introduced as a recognizable BO character from the moment she was introduced. Then it continued to develop from there. But we knew to expect her face in the near future. We know to expect Akai's face in the near future as well. We don't to see Bourbon's face again in the future because we've never seen it.

I don't understand what point you are trying to make.

What I have underlined in bold is my main concern with this theory. If Akai is going to fold into Okiya, or vise versa, one of the character qualities will be lost. you have named "mannerisms" which is basically what I like about Okiya separate from Akai. I feel that Okiya is a uniquely developed character from many characters who have claimed to like the color "black" because: he doesn't act like the world is going to end, he isn't particularly intense, and he does things like cook and water plants, some very domestic skills. Akai....well, he is a guy on the verge of getting his rival and enemy Gin....that same guy cooking and watering plants? That is really funny.

I think we are thinking of two different things.
When I talk about "Okiya's character folding its development into Akai", I mean that when a disguised character's identity is revealed, everything we learned about the person while disguised- their actions, attributes, and words- automatically "belongs to" the real identity because they are by definition the same person. Of course, the reader must take into account that the character may have done things they wouldn't normally do as part of the disguise, so the reader has to sort out how much was acting and what was the real person's personality showing through. A perfect in-manga example is Dr. Araide wondering if Vermouth had a genuinely good side or if she only meticulously mimicked the doctor's compassionate personality.
When a character gives up their disguise; they generally lose any reason to continue acting, so they revert back to how they were before. If you liked the way the alias acted, you might be disappointed. Unfortunately, no matter how much you like the disguise's attributes, you can't influence the reality that it was all an act. Similarly, wishing that Okiya was a separate person can't be used as evidence that Okiya and Akai are different people. If I were to compare it to pairings, no matter how much someone likes AixConan, it doesn't change the fact that Shinichi's current primary love interest is Ran. (NO, WE ARE NOT GOING TO HIJACK THE OKIYA THREAD WITH WHO IS BETTER FOR CONAN, WHO WILL CONAN ULTIMATELY END UP WITH, OR WHETHER OR NOT CONAN LIKES AI A LITTLE. IT IS NOT RELEVANT TO THIS POINT. IT'S AN OBVIOUS AND UNDEBATABLE FACT THAT RAN IS THE PRIMARY CURRENT LOVE INTEREST AND IF YOU BELIEVE OTHERWISE YOU ARE DELUDING YOURSELF AND I WOULDN'T WANT TO TALK TO YOU ANYWAY. THAT IS ALL.)

I can see Gin dressing in disguise too, but not his whole face, and not as someone like Okiya. Maybe a wig and sunglasses that will come off in the same episode....then again, Gin isn't that type either. Hiding behind a mask shows you are in fear...and what does Gin have to fear? Except the cops, which he can avoid just by being quiet like he did in several other episodes...

No matter what you think about Gin's personality, you can't change the fact that Gin apparently disguised himself to some unknown degree because he was concerned that the police might be on their way.

[Abs.]

1. Who broke Chekhov?  

2. I took a few quick snaps of Okiya in the keyhole of volume 60.

Spoiler:

I suppose you can decide for yourself what color that is, and if it's the "real" color of Okiya's hair or not.