Taichi, the father, was able to remarry the young and beautiful Reiko and was living happily every day. However, even though this family appears to be happy at first glance, abnormal acts are taking place behind the scenes. It is the unforgivable act of incest between the stepmother and her son. Feeling guilty towards her husband, the stepmother tries to stop her son, but the son's actions become more and more bold as he enjoys the thrill...