During the sex training camp at the university, a group of girls from the dance club are forced to squeeze and slap each other in order to practice their sex moves. The girls decide to have a "joint party" where they will "squish" and "suck" at each other's breasts. They decide to do it with a condom, which is a sexual lubricant, rather than with a penis, because "the sex is so intense" . They also decide that they will have sex with Touma and Silvia, who are going to a hot spring.