Father, Yoshiyuki of Junichi lived on two with Junichi through a single person since I lost a wife in the professors of the university where Junichi went to more than ten years ago. One day, as for Junichi, a remarriage is told to Yoshiyuki. And it was the Aya which was classmate of Junichi to have been introduced as Stepmom…. As for "the Stepmom, "the Younger Sister collects an upper-class student" classmate" and Episode 2 Episode 1.