Hino-kun is good-looking – and a rumored delinquent. Although in reality, he is a kind-hearted high school student who looks after his young nephew. He can see that Mizusawa-kun is good at making sweets, so for the sake of his fatherless nephew, he asks him to, "Please marry my older sister!" But instead, he receives a reverse proposal from Mizusawa saying, "I want to marry you."…?!