Introduced in volume two of the manga, Kuchiki becomes a full-member of Genshiken together with Ogiue in volume four apparently after being kicked out of the Anime Club. Kuchiki is a very abrasive individual, with a loud and obnoxious style of speech and no qualms about doing indecent or improper things (such as spying on girls). He was a part of the Anime Society before he joined Genshiken. He wants to be nicknamed Kuchi (クッチー Kucchī?) and enjoys it when people use this nickname. He is also not ashamed to cosplay.

Kuchiki is actually the second-best fighting game player in Genshiken, next to Kousaka. He twice expects himself to be named the next Genshiken president, only to be passed over by Ohno and then Ogiue. Mostly a background comedic character, Kuchiki is used as a goad for a good many of Genshiken's slapstick and off-color jokes. One might even consider him a boke to the rest of the Genshiken's tsukkomi.

In the relaunch of the manga, it is revealed that Kuchiki doesn't need to look for a job since he's pretty much guaranteed to have a job at a local bank thanks to family connections.

(Source: Wikipedia)