Hiyoka is a 15 yr old who is a part of a highschool gang called Firefly,due to her attending Zuri High. It's a "good" gang who mainly stop bad gangs such as Black Shark and members of the Yakuza who cause problems in the city. She is a kind,cute,serious,stoic and strategic girl but she flusters easily. She knows that Mayashi has a crush on her and pretends not to care but for some reason gets jealous when she's around other girls. Her other friends are Hax and Akiko.