Kippei Katakura is the handsome playboy of the school. After ditching school to play around with a girl on the roof, his friends ask him to go play around. However, he received a phone call, telling him to go home right away. His 5 year old cousin, Yuzuyu, is staying with him, and he is the one in charge of taking care of her.

Yuzu is becoming some-what of an outcast at school, because she is motherless. She has Kippei though, so she'll be okay, but what happens when a seriously Kippei-crazed girl shows up?

The preschool's having an athletic competition.