When Yu was 18, she became pregnant and gave birth to Tatsumei. Her father disappeared when he found out she was pregnant. Despite the opposition of those around her, Yu gave birth to Tatsuaki alone. She desperately raised Tatsumei single-handedly. Tatsumei entered university and finished raising his children. The two were good friends, partly because they were close in age. The way they went shopping and traveling together was more like friends than parent and child. One day, Tatsuaki took advantage of her summer vacation to invite her girlfriend Yu to a hot spring trip...
