Married for 25 years. Natsuko's daughter is now an adult and she lives an ordinary but happy life. She has a good relationship with her husband and doesn't feel any particular dissatisfaction. That's when Natsuko meets Kanno, a senior student of hers. At first, it was just a casual relationship. However, Kanno fell in love with Natsuko at first sight. Kanno knew that it was a forbidden relationship, but he was a pure and modest young man. Seeing his honesty reminded Natsuko of her youth. "I'm seriously in love with you, Natsuko..." "What are you talking about already?" "I know that sounds strange. You have a husband and Yuna-chan, Natsuko-san... I know that it's an unrequited love..." "...Kanno-kun..." "Finally...can I hold your hand?" "Huh?... What should I do..." "With this... I'll give up..." Natsuko instinctively holds his hand. At that moment, the Kokoro that had been sleeping inside her awakens. A love that she had forgotten for years... Those feelings destroy her reason and develop into a forbidden relationship.