Ken was a short thin boy, he had black hair and long thin eyebrows.
Ken was rude and spiteful, happy to make a problem of himself. Unlike his two friends he was the only one to take proper care of his school uniform, take that how you will.
Ken was a member of a gang of young delinquents, at one point he, Go and Dosu-Roku follow the girl Miki Makimura and her freind Akira Fudo home, taunting them. Miki retaliates and insults them before slapping Ken and Go in the face. Dosu-Roku grabs her arm furious at the abuse hurled at them and he tells Go and Ken to block the path for Akira, however she is saved by the sudden arrival of Ryo Asuka who chases the gang away with a gun.
Later on, after Akira had become the titular Devilman, the thuggish trio stop Akira and Miki again. The three of them wanting to get payback, especially now Ryo was nowhere to be seen. Go tries attacking tough, but immediately gets mocked by Miki, who jokingly urges the boy to kill himself. Go rages and shouts back before Dosu-Roku steps in and pulls out his knife, and action that is then mimicked by Ken and Go. Miki pulls out a knife of her own, having expected this, but Akira pushes her behind him and beckons the three to came at him. Go goes fist but gets hit in the face and knocked to the floor. Ken lunges at him, but suddenly gets backhanded, causing him to drop his knife and fall to the floor. Akira then sets his eyes on Dosu-Roku, and violently knocks him down.
- In the film, 'Devilman: The Birth', Ken and Go's roles are replaced by Dosu-Roku and Manjiro , with Masa taking charge.