Okada, in his late 20s, is an employee who commutes to and from work by train every day. He regularly sees high school student Yui, who is very well-built and in excellent health. In his daydreams, he imagines what taking her as his wife would be like. One day, he accidentally touches Yui indecently, but she does not react with either physical or verbal defence. Okada becomes more daring and invites Yui to a love hotel. After having fun with Yui there for some time, he realised this was not his smartest idea. So, when he apologizes, Yui tells him her view of what has happened so far …