Mizuno has a rather dubious dream about Keigo. The next day the Underwear Society go on an overnight trip to a beach hotel where Nayu's grandmother used to stay. Mizuno brings her old school swimsuit which the girl's accidentally wreck whilst trying to remove the nametag, so they take her to buy a new one. After rain cancels the swim session, the girl's go to a hot spring, where Hiroki passes out over hearing the girls, and is embarrassed to find that they carried him naked over to his bed. After the girls give Mizuno a makeover, the hotel mistress tells them about Nayu's grandmother. After a trip to the beach the next day, everyone heads back all sleepy, although Hiroki is annoyed that they didn't discuss any club activities the whole time.
Minori Chihara
Nayu Hayama
Sayuri Yahagi
Haruka Shiraishi
Minako Kotobuki
Yako Jingūji
Takahiro Sakurai
Keigo Hayama
Yoko Hikasa
Kiyono Amahara
Yuudai Sato
Hiroki Komachi
Sayaka Ohara
Tamaki Mizuno
Ako Mayama
Tsukamoto-sensei
Gara Takashima
Yōko Sagisawa
Tanuki Sugino
Principal
Katsuhisa Houki
Ōkuma-sensei
Motoki Takagi
Kōta
Naoko Sugiura
Kaori Seto
Takashi Onozuka
Komachi's older brother
Toshiyuki Morikawa
Tsuzuki
Umeka Shouji
Chigusa
Yuichi Nakamura
Tanihara-sensei
Yuiko Tatsumi
Suzuki
