Tatsumi Azuma, a sociable third-year student at Keyaki High School, crashes into second-year Shunpei Eguchi and fractures his hand. But the stone-faced Shunpei is no ordinary student—rumor has it he'll kill anyone who so much as looks him in the eye! Afraid of retaliation, Tatsumi tells Shunpei he'll do anything to make up for his blunder. Thus, Shunpei puts him to work by making him help out at his family's bathhouse, Sakura-no-yu!