Mother Anna who lives with her two sons Takahiko and Shuji. On the surface, they had a happy family life, but Anna and her eldest son, Takahiko, had a secret. It had a physical relationship while being a parent and child. The fact that they were once separated due to family circumstances has instead brought them closer together. However, she happens to be seen by her second son, Shuji. Shuji suddenly becomes aloof and tries to keep a distance from the two, but Takahiko wants Anna even more, thinking that this is a good thing.
