The Underwear Society goes on an overnight trip to the seaside ryokan Nayu`s grandmother used to visit. The girls of the society are bursting with excitement, but their explicit conversations put Komachi on edge. Komachi finally has the chance to relax by himself in the men`s bath, but he passes out when he hears the girls` thrilling conversation. When he finally comes to, Komachi finds himself wearing underwear and cannot hide his dismay at being seen by the girls.