Name: Tsunan Tsukioka

Aliases: Katsu, Katsuhiro

Age: 23

Height: 5'11"

Weight: 211 lbs.

Body Size: B 42"-W 33"-H 35"

Hair: Black

Eyes: Dark Green

Blood Type: O

Weapon: Sakurdetsu-Dan (home made stuff explosives)

Along with Sanosuke, Katsu was one of the youngest members of the Seikihoutai. He shares the same feelings as that of Sano when comes to hating the Meiji Government, but he hasn't tried to forget the past. When the Seikihoutai disbanded, Katsu moved to Tokyo and began a new life as a painter, very different from what his speciality is, handling gunpowder and ammunition, under the name Tsunan Tsukioka. Katsu painted on color woodblock prints and eventually became a very popular artist, painting popular samurai of the past. When it was discovered by Sanosuke that he had painted a picture of the Seikihoutai captain Sagara, himself and Sano as children, he was visited by his old friend.

Katsu expressed his plans, wanting to reform the Seikihoutai to get revenge on the government for ruining the group's name by bombing important government buildings. In his closet was stored hundreds of bombs ready for use. Sano, who prefers his past over his present life, joined his friend Katsu, but their plans were stopped before they even got off the ground by Kenshin.

Although Kenshin had tried to convince Katsu that what he was doing was wrong, Katsu refused to listen to one who helped bring up the Meiji Government. Instead, Katsu quit his occupation as a painter and began to work on a newspaper that expressed his hate for the government. The final masterpiece of Tsunan Tsukioka was that of his master, the one who looked up to, Sozou Sagara. In the meantime, Katsu stayed close to Sanosuke, working as an accomplice for him. It was Katsu who supplied Sano with the pineapple bombs that he used to destroy Makoto Shishio's Rengoku.