At this school, when it's time to switch to summer uniforms, the swimsuits become the uniform. There was some confusion at first, but once you get used to it, it's surprisingly convenient and popular among the girls. Of course, since they're substitutes for uniforms, students wear them from home and take the train to school. It's a bizarre sight for those seeing it for the first time, but it's just an ordinary day for locals. It's a fact that the stimulation is quite strong for male teachers. Naturally, there are girls who take advantage of this to play pranks, testing the teachers' ethics daily. And even those teachers are just males at heart. Mistakes naturally happen. There's no man who can resist the sight of many cute girls in swimsuits! So it can't be helped if school life becomes lewd...
