Yuu lives alone in a boarding school. His fulfilling student life is coming to an end, and finally it's time for his graduation ceremony. On his lonely way home, his stepmother, Wasaki, comes running up to him with a smile. He is happy to be reunited with the woman he admires, and at night they celebrate his graduation together... The two talk to each other, trying to make up for the time they were apart. Then, Wasaki's slightly moist lips quietly close to his, saying, "This is my gift to you, now that Yuu've grown up." On this day, he takes another step towards adulthood.