Koichi Akiba appears in Episode #8 "A Lost Soul In The Darkness". He lives with his mother, younger sister, and paternal grandfather. However, being a sloppy investor and businessman, he plots against his wealthy grandfather to get money. He's insane but the real brains of the outfit, basically conning his homicidal mother into thinking that her airhead daughter is plotting against them too.

(Source: AbsoluteAnime)