Mary, a resident of a certain town, struggles with her accounting work, housekeeping duties, and balancing home life. As her frustrations grow towards the community she lives in, one day, the chairman, Nakata, asks her to participate in a mama san volleyball tournament. Unable to refuse, Mary reluctantly attends practice sessions every Saturday, but much to her surprise, there are only a few middle-aged men present. These older gentlemen quickly undress Mary, making lewd comments and touching her generous body while giving her sexual harassment lessons...
