Due to his parents relocating to a different area, Kazunari Usa, a high school freshman is set to enjoy a new independent life, living alone. He's looking forward to a carefree teenage life, devoid of the burden of weird individuals. However, when he moves to the Kawai Complex, a boarding house, he discovers that it's anything but ordinary. The occupants of Kawai Complex are all quirky characters. Kazunari's roommate, Shirosaki, is a deviant and a masochist. Mayumi Nishikino, a borderline alcoholic office lady, has developed a dislike for couples due to her poor fortune with men. Furthermore, Sayaka Watanabe, a seemingly innocent college student gets a kick out of leading men on. Despite the unusualness of his new surroundings, Kazunari considers leaving when he meets Ritsu Kawai, a timid senior student. Eventually, he finds himself falling for Ritsu.