In an old mansion near a school in the town, there has long been a legend of an oniba, which has been feared by the students. Miyazaki, a member of the baseball club, was one of them, but one day, a ball he hit during practice flew into the mansion. When he fearfully climbs over the fence and goes to retrieve the ball, he finds Reiko, a mysterious big-breasted woman in the mansion... And Miyazaki, who has been caught, has his cock erected contrary to his heart, and is played with by being sandwiched between big tits while being preached.