It's been three years since he left his parents' home. Yuu enrolled in a boarding school to let go of his feelings for his stepmother, Yuka. But on the day of his graduation ceremony, he saw her running up to him with a smile. He felt the hidden feelings well up again. That night, when she got drunk after celebrating just the two of them, Yuu took her back to the lodging. Yuka, aware of his feelings, gently kissed him, saying, "This is your congratulations from your stepmother on your graduation." Guided by his stepmother, he took another step towards adulthood.