Chisato had been married for 25 years. Her daughter was now an adult and she was living an ordinary but happy life. She had a good relationship with her husband and wasn't particularly dissatisfied. At that time, Chisato meets Matsuki, a university student who attends the same university as her daughter. At first, their relationship is casual. However, Matsuki fell in love with Chisato at first sight. Matsuki was a pure and modest young man who knew that it was a forbidden relationship. Seeing his honest attitude reminds Chisato of her youth. "I'm seriously in love with you, Chisato..." "What are you talking about already?" "I know that sounds strange. Chisato-san has a husband and China-chan... I know it's an unrequited love..." “…Matsuki-kun…” "Finally...can I hold your hand?" "Huh?...What should I do..." "I'll give up on this now..." Senri instinctively holds his hand, and at that moment, the excitement that had been sleeping inside her is awakened. A love that had been forgotten for years... Those feelings overwhelmed his reason and developed into a forbidden relationship.