Thanks to his parent's job transfer, he's now boarding at Kawai Complex. He's an honest high school freshman, and he admires Ritsu, an older girl living in Kawai Complex as well.

A sophomore at the same high school as Usa. She's always reading a book, and because of that she has few friends and shows little interaction or expression, but sometimes she does show a few cute sides expected of a high school girl. Ritu's mother is the owner of Kawai Complex.

Usa's roommate. His nickname is Shiro. His job is unknown. He's a true masochist. He's completely harmless, and actually prefers it when people harm him.

A beautiful, big-breasted, glasses wearing office lady. But her luck with men is abysmal, and since she's always getting thrown around and dumped by different men, her mood swings are fierce, and sometimes Usa and Shiro become the victims of such a swing.

At first glance she's a cute college woman, but she's sly, clever, and dark when it comes to the way she handles men, and she often leaves accurate criticisms of Mayumi's ability as a “bad-man catcher”.

Kawai Complex's landlord, she's also in charge of cooking and caring for everyone there. Ritsu is her grandniece.