Shishunki no Obenkyou is a multi-volume doujinshi, and only the first part will be animated. And the first chapter of this hentai will show us the beginning of the story, about two classmates of Kasuga and her school friend Kobayashi. The girl has an irresistible curiosity and a desire to find out what men look like below, i.e. she wants to see a real penis, and is constantly tormented by these thoughts not knowing what to do.

On the same day, her classmate Kobayashi boasts to her about the results of his exam with the maximum score, and the girl matures a simple plan on the go, in response to this, she says that she can beat him in school, and they make a bet: whoever gets the worst score on the next exam will do whatever the winner wants. When another exam was passed and they showed each other their results, they saw that they had a draw, and therefore it was decided that they both should fulfill each other's desire. The boy, not preparing for anything like this modestly, asks her to give him an eraser, which in turn, as a wish, Kasuga asks him to show her a member. At first, Kobayashi was very embarrassed, but under the pressure of the girl, he gave up, after a long and fascinating study of each other's bodies, they had sex, although none of them even realized that it was actually him. That's how this romantic and funny story of two inexperienced teenagers begins.