I had to transfer schools due to my parents' circumstances, and it was my first day. I entered the classroom with a pounding heart, and it was a normal class with cute girls. However, as soon as the opening ceremony ended, everyone started changing into swimsuits, and I was made to change too, and class started in swimsuits. I couldn't stop my erection with the unexpected development and erotic swimsuit appearance. Toa Kiyomiya helped me because she couldn't stand seeing me like that. From that day on, my erotic school life began, where I get an erection during class and have sex during breaks.