Underwear Summer Training Camp!.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 while 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...