Sayuri, a slender milf who lost her husband at an early age, raised her son Takeo all by herself. Takeo had no rebellious phase, and they lived a peaceful life together. However, one day, his classmate Koji suddenly showed up at her house, revealing deep-seated resentment stemming from a conflict with Takeo. Though he left that day, the next day he returned with his delinquent friends, and the situation quickly spiraled out of control.