It is parents day at Asahigaoka Branch School, and the presence of Yukiko Koshigaya (Natsumi, Komari, and Suguru's mother) makes both Natsumi and Kazuho nervous. Renge and Shiori (daughter of resident police officer, episode 4) play with a ball together, and it somehow turns into a philosophical discussion. Natsumi and Renge set up a fish-tank for Salt, a crab the younger girl wants to keep until the weather warms up again. Pleased with Natsumi for helping her little sister set the tank, Kazuho invites her for dinner, but the planned meal shocks Renge.