Commander of the Shinsengumi, a special anti-terrorism police force. He is the man who organized the Shinsengumi, and he is deeply trusted by his subordinates. However, he is in love with Shinpachi's older sister, Otae, and frequently stalks her. He often ends up naked before he even realizes it, making him a dangerous individual in his own right. He thinks of himself as Guest's father figure.

The cool-headed Vice-Commander of the Shinsengumi. He established the Kyokuchu Hatto (Code of Conduct), and when he draws his blade, he is feared by terrorists and subordinates alike as the "Demon Vice-Commander." 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 has a dark, scheming personality. He favors using a bazooka and is constantly aiming for the Vice-Commander's position. He tries to slack off on his duties at every opportunity. He is a total sadist. He likes Guest and feels the urge to tease them.

A Shinsengumi spy whose only redeeming quality is his plainness, constantly pushed around by his unreasonable superiors. While he is often seen playing badminton or kabaddi during work hours, his skills as a covert agent are supposedly excellent. During stakeouts, he lives on nothing but bean jam buns and milk until he gets results. He respects Guest.