|This article is about a/an ally in Choudenshi Bioman.|
Shūichi Kageyama (蔭山 秀一 Kageyama Shūichi?): Thinking himself an orphan, named Kōichi Nakamura (中村 公一 Nakamura Kōichi?), he learns he is in reality Shūichi Kageyama, the son of Doctor Man and basis of Prince's design. At first, Doctor Man tries to get him to join Gear, but Shūichi rejects Doctor Man. Eventually, Shūichi finds and joins Professor Shibata. Later, he helps the Bioman ultimately defeat Gear. He manages to convince Doctor Man to help them stop the bomb that could destroy the whole Earth through the use of human emotions. (Played actor by Hidenori Iura) In the English dub his name is Sonny.