Makoto leads a school life while living in a dormitory. Three fulfilling years came to an end in the blink of an eye, and the graduation ceremony finally came. At his parent's house, the woman he admired, Mariko, remarried her father, and he hardly ever returned home due to her embarrassment. However, on the way home, Mariko, who became her mother-in-law, suddenly came to celebrate her graduation. That night, at her place of lodging, she gently kisses him, saying, "A present for grown-up Makoto." Guided by his longing mother-in-law, he climbs the stairs to adulthood again.
