Leader of the Oni-gumi and Ken's older sister. The strongest delinquent in Japan. She wears a school jacket draped over her shoulders with only a sarashi chest wrap underneath. Her favorite weapons are a nail-studded bat and her fists. She's challenging Arc-Cute simply to see if they're actually strong. A high school sophomore. Clueless about romance. She has long black hair and red eyes.

Vice-leader of the Oni-gumi and Hana's younger brother. The second strongest in Japan. He wears a school jacket over his shoulders with a sarashi wrap. He worships his sister Hana like a god. His favorite weapons are his fists and brass knuckles. A high school freshman. He calls Hana "Sis." He has short blonde hair, red eyes, and wears an open school jacket over a red short-sleeved shirt.

Boss of the mafia group Arc-Cute. A high school sophomore in the same class as Hana, though they've never spoken. She apparently falls for anyone stronger than her, regardless of gender. She fights skillfully with knives and handguns, though she's also proficient in hand-to-hand combat. She has a pink ponytail, magenta eyes (not pink, 100% magenta!), and wears heart-shaped sunglasses, a black knit sailor uniform, black pants, and a black coat draped over her shoulders. Cold-blooded but an airhead. First person: I (formal). Second person: you.

Combat specialist for Arc-Cute. Tiara's right-hand man, the dumbest member of the group, and the one with the most raw physical strength. He has a policy of not using weapons. Tiara and Sue are always calling him an idiot (because he really is one). A high school sophomore in the same class as Tiara. He has short pink hair, red eyes, and wears an emerald green tank top with sky-blue pants. A muscle-brained extrovert who aggressively befriends anyone he takes a liking to. First person: I (casual/masculine). Second person: you (blunt).

The brains of Arc-Cute. The smartest member and the physically weakest, possessing the exact opposite traits of Powered. His IQ is roughly one billion. Like Ken, he worships Tiara as a god. A middle school seventh-grader. He has short black hair, red eyes, and wears a red hoodie with black pants. Calm and cool-headed, but his brain short-circuits when he sees something that defies logic. First person: I (polite/masculine). Second person: you.