On a night when the Mizumi couple happily returned to the husband's family home, wife Saki recalled something that had intrigued her ever since her marriage—the existence of her reclusive brother-in-law, Kenji, who had been shut away on the second floor. For decades, he had lived as a degenerate youth rotting in a decaying room. That night, after finishing her bath to soothe the fatigue of the trip, Saki stepped out of the bathroom and encountered Kenji devouring food noisily from the kitchen refrigerator. But in his eyes, the sight of the woman from Tokyo—his sister-in-law Saki—shone dazzlingly, captivating his gaze completely.