Ever since Tatsuya's father died when he was young, Hikaru and Tatsuya have lived together. Tatsuya has come to love Hikaru, who loved him wholeheartedly, as a woman. Without realizing his feelings, Tatsuya has come of age and is soon at age to start working. He doesn't want to get a job and leave Hikaru, but he also doesn't want to betray Hikaru, who has seen him through to graduation... At the same time, Hikaru is worried that she has not acted like a mother at all, so she invites Tatsuya on a trip to a hot spring.