Anokata being Shinichi's dad or mom, Agase, Vermouth, Gin, Akai, Jack Black, Yoko Okino, Toichi Kuroba, Haibara's mom or dad, Ran's dad or mom... These are all wild theories wth no real evidence to back them up and just created by thinking "the identity of the Boss must be a twist that no one saw coming". Just because it is hard to guess doesn't mean it doesn't have a logic that fits a certain pattern. I will start my reasoning by posting the obvious and necessary link, since many people ignore the facts; http://www.detectiveconanworld.com/wiki/The_Boss_of_the_Black_Organization#Known_canon_information Now, since the impression we got so far points towards the gender of the Anokata being a he rather than a she, I'll assume the Anokata is a he. My theory is that the Anokata is one the people that were introduced in the same chapter that Vermouth first appeared. Those characters are; Naomichi Mugikura, anchorman for Nichiuri TV. Yoshiharu Tawara, university professor. Yasuo Mihei, baseball team owner. Naoya Tarumi, music producer. What these characters have in common that they all dress in black, since it was a memorial, and all of them are figures of power. These traits are definitely identifiable with the Anokata. What's more, since this certain chapter has many memorable events it's viable for the Anokata to have made an appearance. Among those characters Naomichi Mugikura is the more likely candidate, since he made multiple appearences, but you never know.
Last but not least, Yoshiharu Tawara is a university professor just like Sherlock Holmes' archnemesis, Professor Moriarty.