After three years of living away from home in a dormitory at a distant school, Yuu finally graduates. On the day of his graduation ceremony, his stepmother, Marina, comes running to him with a radiant smile. That night, as the two celebrate his graduation alone together, Marina becomes overwhelmed with joy and drinks too much, eventually passing out drunk. As Yuu prepares to escort her to her lodging, she gently guides his hand toward her chest. Enveloped in the warmth of the woman he has long admired, Yuu takes another step into adulthood.