Born into the mayor's family for generations, Iku Kazama is a high school girl known for her excellent grades, versatility in sports, and a for being a well-behaved honor student. However sge was considered her classmate Shiro as a rival. Born into a yakuza family for generations, Shiro was a genius child who was feared by the people around him, but had superiority and good manners, and his school performance was always the highest. It was Ii who tried harder than anyone to lose to Shiro, but he hides it so that no one knows it.

Shiro, said one day, "If I win the next test, go out with me." Iku who thought that it was a strategy to upset himself, accepted the bet, but lost again in the test.