After graduating from university, Akira immediately moved away from his family and started living in the school dormitory. During this time, his father also remarried another woman. Akira didn't resent his stepmother at all; in fact, he was very grateful as she always cared for him, worried about him, and helped him forget the feeling of loneliness when living alone. Finally, on the day of the graduation ceremony, Akira's father couldn't attend due to work. Thinking that he would have to go through this important day in his life alone, suddenly, his stepmother was waving and smiling from afar. They celebrated together, and his stepmother drank a lot of alcohol, so Akira had to take her back to the hotel. As he was about to leave, his stepmother held him back, gave him a passionate kiss, and confessed her feelings to him. And their forbidden love affair began from that moment on...