Kondo Hideki is 42 years old. As the only son of the president of a pharmaceutical company, his future was secure, but for some reason he took a leave of absence last year. He now lives at home with his parents. However, he is currently concerned about his father's mistress, Reika. A woman more than a decade younger than him, she is a treacherous woman who has ingratiated herself with his father, who is the president of the company. Hideki's suspicions about her are on the verge of exploding. Then his father goes on a business trip, leaving Reika behind at home. Seizing this as an opportunity, Hideki puts his secret plan into action...