He has an identical twin brother, Daisuke Tsuchiya, who is also an actor, playing an evil copy of KirinRanger in episode 25. This was mirrored in the Metal Hero series, Juukou B-Fighter, where Daisuke Tsuchiya played the protagonist Takuya Kai/Blue Beet, while Keisuke played his evil clone Shadow/Black Beet. In the next series, Ninja Sentai Kakuranger, Keisuke and Daisuke Tsuchiya played Jirou and Tarou respectively. In GoGo Sentai Boukenger he appeared as Natsuki's father