Shiro was born when Nanao was 20 years old. Despite the opposition of those around her, Nanao raised Shiro on her own. As they were close in age, the two were more like friends than parent and child. When Shiro became an adult and his university life settled down, Shiro invited Nanao on a hot spring trip. Nanao was in the mood for a normal trip, but Shiro had a confession he wanted to make...