Yu attends a boarding school. The fun student life ends in a blink of an eye, and on the way home from the graduation ceremony, Yuu sees a smiling woman running up to him while walking with his friend. The person who visited with her smile was her mother-in-law, Hijiri, who was secretly in love with her. Yuu's heart is thrilled at the celebration of being alone with her crush. That night, she drank too much and sent her unsteady to her inn. Hijiri accepts his feelings and gently kisses her, saying that she is "a present from me." And Yu begins to take a step towards her adulthood.
