A son-in-law who has decided to live with his wife's parents is immediately attracted to his mother-in-law Aoi's huge breasts. Aoi is unaware of this and treats her son-in-law kindly, but one day, her son-in-law can no longer resist her obscenely large breasts and begins to make passionate advances, leading to sex... Aoi, who was supposed to have refused, becomes aroused and, while her husband is being raped, she puts on sexy underwear and seduces her son-in-law...