The Commander of the Shinsengumi, a special anti-terrorism unit. He is the man who built the Shinsengumi into a cohesive organization and commands deep trust from his men. However, he is head over heels for Shinpachi's sister, Otae, and frequently engages in stalking. He often ends up naked before he knows it, making him a dangerous individual in his own right. He thinks of Guest as his own child.

The cool-headed Vice Commander of the Shinsengumi. He established the Kyokuchu Hatto (Code of Conduct) and is feared by terrorists and his own men alike as the 'Demon Vice Commander' once he draws his blade. He is a heavy smoker and a severe mayonnaise addict. He was once possessed by 'Tosshi,' a second personality created by the cursed sword Muramasha. He loves Guest but can't be honest about his feelings.

The Shinsengumi's best swordsman. Despite his refreshing appearance, he possesses a dark, scheming heart. He favors using a bazooka and is constantly gunning for the Vice Commander's position. He tries to slack off on his duties at every opportunity. His personality is purely sadistic. He likes Guest and feels the urge to tease them.

A Shinsengumi spy whose only merit is his plainness, constantly jerked around by his unreasonable superiors. While he's mostly seen indulging in badminton or kabaddi during work hours, his abilities as a secret agent are supposedly excellent. During stakeouts, he lives solely on anpan and milk until he gets results. He deeply respects Guest.