Momoka Izumi is a quiet, diligent honor student. She never skips classes and always watches swimming lessons. But she can't actually swim, so as her homeroom teacher, she offers to give her one-on-one after-school lessons. Her progress is remarkable, and Momoka's ngây thơ eyes are filled with joy. However, the school swimsuit suits her so well, even though she's a slender girl with pale skin. When wet, the swimsuit clings to her skin. The navy xanh dương swimsuit accentuates her pale skin...