Abs. wrote:
We don't know anything about Ran's grandparents.
Later Edit: This is outdated. Please refer to
here for the most recent version.
We don't know anything about Kogoro's family either and its ususual and suspicious considering he is one of the top three freaking main characters. Conspiracy theory rant time! (a repost)
There is a conspicuous absence of anything pertaining to Kogoro's family background. He's a main character and absolutely nothing has been mentioned even in passing about any of his kin beyond Ran. Considering the length of the manga and that character history stories are otherwise quite common, I believe this omission is intentional. I can think of three situations that would account for the censorship.
a) Someone(s) in Kogoro's family has a critical connection or position in the Org. I do not support the theory that Kogoro himself is part of the Crow Corps, but with the family name "Mouri", and its difficult-to-ignore resemblance to "Moriarty" from the Sherlock canon, I think that this theory concerning relatives on the dark side holds thematic appeal.
b) Someone(s) in Kogoro's family was a victim of the Org, and that the circumstances/mystery behind it are a major clue to one of the central mysteries like the identity of the boss, or the org's name, etc.
c) Kogoro's background relations are not important or non-existent. I think this explanation is weak because it goes against Gosho's style. The vast majority of the main and secondary characters have had some member of their family brought up, often as participants or suspects in cases, as motivation for why the character is where they are now, or simply mentioned in passing. The idea that Gosho would ignore using Kogoro's family for any case/plot purposes without a genuinely good reason for (as of now) 717 chapters is unreasonable.
The reasons why a relative of Kogoro can't be introduced too early could be one or more of the following:
a) It would be too big of a hint.
b) It would call unwanted attention and suspicion where Gosho does not yet want it.
c) It serves as a major plot key which will enable Conan to solve a very important mystery.
Given that this censorship on Kogoro's kin has been going on since the very beginning of the manga, it would be logical to assume that the reason is pertinent to the overarching mysteries - namely what is the true nature of the Org, who is the boss, and what is its goal.
In short, I believe it is reasonable to assume that Kogoro has (or had) one or more plot-significant family members who have (or had) vital connections to the Black Org, as either victims or members.