Aoi recently noticed she has gained some weight and decided to start attending a swimming class. However, the class is filled with male participants. Naturally, the men are captivated by Aoi's beautiful figure and begin subjecting her to one sexual harassment incident after another. Initially enduring it, Aoi gradually finds herself unable to resist their advances. Forced to wear swimsuits, then made to swim completely naked, the situation escalates rapidly as she slowly succumbs to their actions.