Okada Toshio is an anime producer, author, lecturer and the co-founder and former president of Gainax, which he left in 1992. He has written several Japanese-language books on otaku culture and lectured on the topic as an adjunct instructor at Tokyo University. He is considered the foremost authority on otaku and has been crowned "OtaKing" amongst his colleagues and fellow otaku. [From: AniDB]