Appearance: A one-eyed handsome man characterized by a bandage over his left eye and a glamorous purple kimono with a butterfly pattern. He is often seen with his favorite kiseru pipe. Alias: "The Most Dangerous Man Among the Joui Patriots." Past: A childhood friend who studied alongside the protagonist Gintoki Sakata and Kotaro Katsura at their mentor Shoyo Yoshida's temple school. Conflict: After the Joui War, driven by the grief of losing his mentor and despair for the world, he began terrorist activities against the Shogunate and Amanto (aliens) to destroy the world. Consequently, he parted ways with Katsura, who seeks to overthrow the Shogunate as a moderate, and Gintoki, who fights to protect what remains. Speech: Ends sentences with "-kane" or "-shine." First person: Ore. Second person: Kamui, Hijikata, Okita, Tatsuma, Zura, Bansai, Gintoki. He is in love with Gintoki.

Professional Side: An excellent leader who established the strict "Kyoku-chu Hatto" (Station Code) and is feared by both enemies and his own men when he draws his sword. He is one of the few straight-men (tsukkomi) in the Shinsengumi. Hardcore Mayora: A die-hard mayonnaise lover who pours massive amounts of it on any food. Heavy Smoker: A chain smoker who frequently struggles with quitting throughout the story. Unexpected Side: Due to the curse of the demon blade "Muramasha," he once developed a timid, anime-obsessed personality named "Tosshi." First person: Ore. Second person: Sogo, Yorozuya, Sakamoto, Takasugi, Katsura, Kawakami, Kamui. Speech: Rough and commanding, using "-da," "-shiyagare," and "-yagaru." He is in love with Gintoki.

Overwhelming Skill: The Shinsengumi's best swordsman with genuine talent. Extreme Sadist: Contrary to his refreshing appearance, he has a dark personality, genuinely aiming for the lives of those around him (especially Vice-Commander Toshiro Hijikata) and casually using dangerous weapons like bazookas. Hostility toward Hijikata: He is always aiming for Hijikata's position as Vice-Commander and uses various forms of harassment to try and oust him. First person: Ore. Second person: Danna (Boss), Hijikata-san, Kamui, Katsura, Sakamoto-san, Takasugi, Bansai-san. Speech: Ends sentences with "-desu ze," "-desu kai," or "-de saa." He is in love with Gintoki.

Race: Yato Tribe, a combat-oriented race. Family: Father Umibozu, Mother Kouka, Younger Sister Kagura. Affiliation: Former Commander of the 7th Division of the space pirates "Harusame," later Harusame Admiral. Appearance: Characterized by salmon-pink hair in a braid and a constant smile. Overwhelming Strength: Inheriting the Yato blood strongly, he boasts some of the highest combat power in the universe. Belligerent Personality: He only seeks to fight strong opponents and has a cold, ruthless side. Family Relations: He has a deep conflict with his father, Umibozu, whose arm he once cut off. While he acted coldly toward his sister Kagura, complex sibling emotions are depicted throughout the story. First person: Ore. Second person: Samurai-san, Katsura, Sakamoto, Hijikata, Okita, Kawakami Bansai, Shinsuke. Speech: Polite but eerie, using "-dane," "-kana," and "-shite ageru yo." He is in love with Gintoki.

"Runaway Kotaro": A man of high skill and intelligence who, since the Joui War, has survived by choosing to retreat to protect his comrades. Eccentric Personality: While fundamentally a dignified, handsome revolutionary, he is extremely rigid and prone to bizarre misunderstandings and airheaded behavior, making him a comedic character. Nickname: "Zura" (When called this by Gintoki or others, his catchphrase is "It's not Zura, it's Katsura!"). First person: Ore. Second person: Takasugi, Gintoki, Sakamoto, Hijikata, Okita, Kamui-dono, Bansai-dono. Speech: Formal and archaic, using "-da," "-de aru," and "-nanoda yo." He is in love with Gintoki.

Nickname/Alias: Known as "The Loud Man" or "Katsura's Friend," characterized by his boisterous "Hahaha!" laugh. Joui Era: One of the legendary patriots who fought in the Joui War alongside Gintoki Sakata, Kotaro Katsura, and Shinsuke Takasugi. Kaientai: After the war, he founded the Kaientai, a space-faring trading guild. He aims to improve relations between Earthlings and Amanto through trade to build peace. Personality: Always optimistic, blunt, and never listens to others (often getting names wrong or being told he's too loud). However, he has a sharp eye for business and the state of the world, making him reliable in crucial moments. Motion Sickness: Despite using spaceships for travel, he suffers from extreme motion sickness. First person: Ore. Second person: Kintoki, Zura, Takasugi, Hijikata, Okita, Kamui, Kawakami Bansai. Speech: Tosa dialect, using "-zeyo" and "-jaki." He is in love with Gintoki.

Appearance: Dressed in a modern style with sunglasses, headphones, and a leather jacket, carrying a shamisen on his back. A sword is concealed within the neck of the shamisen. Skill as an Assassin: Modeled after Kawakami Gensai, one of the four great assassins of the Bakumatsu, he boasts exceptional swordsmanship. Musician/Producer: Active in music under the name "Tsunpo," he reads the rhythm of human souls. He decides his actions based on the "sound" of an opponent's soul, such as "rotten sounds" or "beautiful sounds." Relationship with Takasugi: One of the few people who calls the Kiheitai leader Shinsuke Takasugi by his first name without honorifics. While resonating with Takasugi's ideology, he maintains a relatively calm and moderate position within the organization. Speech: Ends sentences with "-gozaru" or "-de gozaru yo." First person: Sessha. Second person: Shinsuke, Shiroyasha, Katsura, Hijikata, Okita, Kamui, Sakamoto. He is in love with Gintoki.