With different game by Cattleya.

Youhei lives a peaceful life together with his mother Kaho, and cousin Fumika. Eventually, Kaho suddenly confesses to Youhei that she is actually not his mother by birth. Even though this depresses Youhei, Kaho assures him that he can continue experiencing her and Fumika, whom she has always treated as a sister, just as if nothing changed. However, a lady claiming being Ikue, younger sister to Youhei's actual birth mother, moves in across the street and asks that Youhei moves in with her. While Youhei is in a condition of confusion, the three women attempt to use their voluptuous bodies to seduce him.