Kazuki Fuuchouin (風鳥院花月, Fūchōin Kazuki?) is a one of the major secondary characters in the manga / anime series GetBackers. In the original Japanese version, he's voiced by Soichiro Hoshi, while his childhood voice is done by Yumiko Kobayashi. (First appearances - manga:act 4 part 1, anime: episode 6)

Source: Wikipedia