One day, Atsushi witnesses a shocking scene: his father, Kenichi, deeply immersed in a depraved relationship with his own mother, Sayuri. Atsushi can't believe what he's seeing, his chest tightening with anguish. Kenichi is training and dominating Sayuri, taking pleasure in her submissive state—and now he demands that Atsushi participate in these twisted acts as well. A shocking turn of events awaits.