Mostly ripping straight from DCW's Boss of the Black Organization wiki article...Shinichi Edogawa wrote:It's impossible that the Boss is related to conan, to haibara maybe but I never read that in an interview, so maybe the fact that haibara would be surprise is a fake.
All the reasonably well confirmed information that is known about the boss from interviews is:
•Aoyama specified that the name of the boss has appeared somewhere in the manga. It was not clarified whether the boss has appeared in person. (The article where this was written has been tracked down and confirmed.) There appeared to be some confusion over later interviews whether the boss actually appeared in person or not, but it is best summarized by "Gosho gave out an ambiguous statement: The Boss has already been come up with/has already appeared; the name also has already been come up with/has already appeared. But which option is the correct understanding, everyone has their own opinion."
•The Black Organization's formal name gives away the boss' name. "The Black Organization" is not the real name of the organization.
•Minami Takayama, Gosho Aoyama's former wife and Conan's voice actor, knows the boss' identity.
•Aoyama revealed that he didn't expect the Detective Conan series to last longer than three months. This indicates that the boss might have been hinted early in Detective Conan.
•The boss chooses the alcoholic codenames for the agents, but does not have one himself/herself.
•The boss is not Professor Agasa.
The known facts about the boss are:
•The boss uses the first few notes of the song Nanatsu no Ko to encode his/her phone number. The number is #969#6261, which was purposefully made non-functional by Gosho Aoyama to prevent prank calls. The number might have a Tottori area code; but it is uncertain because of the way the number, including the area code, was altered to prevent prank calls. It is worth noting that Ai Haibara reacts to the word Kurayoshi – a city in Tottori province, when she notices Shinichi Kudo had taken an interest.
•He/She uses alcoholic codenames for agents.
•The boss is very careful. Vermouth says, “The boss is always careful to the extreme. He’s the type to ruin the plan by overthinking it.”
•Vermouth is the boss’ favorite for an unknown reason and he/she allows her some degree of independence.
•The boss thought Shuichi Akai could become the Black Organization’s silver bullet. In that regard he/she's more like Vermouth than Gin who doesn't believe a single person who can take the syndicate down in one shot exists.
Bits of info that have been circulated by fans, but have not been confirmed by anyone in the English-speaking population
•Aoyama also said that Ai would be really shocked if she discovered who the boss is. “It’s someone that Haibara would never have expected.” This info is attributed to Volume 19: The Case Closed Casebook.