I'm a freshman full of hopes and dreams. I'm ecstatic when Momo-chan, the most beautiful girl in my class, invites me to go and observe the swimming club. Naturally I agree, and when we go with her to the swimming club, we're told that there's an entrance test. I end up taking the test without being swayed, but as the club captain begins the test, for some reason he touches Momo-chan's lower abdomen and says, "Build up a lot like this." As I tilt my head and ask, "Build up a lot?" the senior members of the club smile and say, "We're the ' Sei' swimming club!"