For a few days while renovations are completed, Kumiko agrees to let Naoto, the eldest son of the neighboring Ueda family, stay at her home. The next day, Naoto arrives with his mother-in-law Yūko to visit the Niizawa household. Kumiko's son, Junpei, is excited to spend time with Naoto and feels a thrill at the prospect. However, Kumiko can't forget a certain piece of information she heard from Yūko—that Naoto is still a virgin. Intrigued by this fact, Kumiko takes a bold step when Naoto steps out of the bath. That moment becomes the turning point that drastically changes their relationship.