Mother Anna is raising two sons, Takahiko, the eldest, and Shuji, the younger. On the surface, they appear to be a happy family, but Anna and Takahiko share a hidden secret. Though mother and son, they were once separated due to family circumstances, which deepened their bond into something far more complex. However, Shuji accidentally discovers their secret. He suddenly changes his behavior, distancing himself from the family. Meanwhile, Takahiko feels a surge of excitement over the incident, intensifying his feelings for Anna. As tangled emotions and inner conflicts unfold within the household, their relationships spiral into uncharted territory.