Sumire, my wife's older sister-in-law, suddenly shows up at our home. The three of us are casually drinking together when my wife starts complaining about me, and the conversation quickly grows more intense. Feeling uncomfortable, I try to escape to the kitchen, but Sumire follows me. Unlike my wife, she exudes a mature, seductive charm that pulls me in. This story follows a husband torn by an affair with his wife, becoming entangled in a forbidden relationship with his sister-in-law. A tale filled with hidden desires and inner conflict.