For certain reasons, the Tachida couple decided to take in their brother's son, Makoto. However, their own son, Tetsuya, did not take this well and began to resent the well-behaved Makoto, falling into a sullen state. While Satsuki was concerned for Tetsuya, she was also drawn to Makoto's kindness, eventually leading them to become intimate. However, after that, Makoto changed drastically and began to humiliate Satsuki without restraint. Driven by anger and frustration upon learning the truth from Makoto, Tetsuya forced him to take his erect penis into his mouth. Since then, the two sons began their days of tormenting and training her…
