Keiko Natori is a housewife in her first year of marriage. Her husband is Shinichi Natori, who is elite and kind. She has her best friend Yuka and her younger sister Shiho Aihara. They all wish for Keiko Natori’s happiness. Keiko Natori enjoys her happy life until Keiko Natori begins to suspect that her husband is having an affair. At first, she suspects her best friend Yuka is the one who is having the affair with her husband. She then suspects someone else close to her.