Erection... It is a physiological phenomenon that occurs when a man is aroused. It is difficult not only to hold it down, but also to keep it standing. However, if the beloved girlfriend exposes her naughty appearance without worrying about the camera, men will exceed the limit! Blowjobs, Titty Fucks, Handjobs, Sex, and even Swapping! Four couples have a gachinko battle with a prize of 1 million yen!