A boy who plays around and doesn't listen to his parents even though he's preparing for the university entrance exam. One day, Yotsuba, a tutor, came to meet such a hero. A hero rebels against Yotsuha, who indifferently tries to educate him. In the midst of all this, she suggests that if she learns from Yotsuha, she will give him a kiss as a reward. At first, he was a mocking hero, but when he saw Yotsuba's seriousness...