This is a documentary that depicts how professional anal developer Moribayashi Genjin makes a girl's ass cum. She resists desperately at first, but she becomes annoyed as he continues to forcefully expand her anus. Eventually, her anus, which has been expanded with toys and dicks, grows to the point where it can accept two simultaneous holes being fucked by men with big dicks, and she finally cums over and over again in anal orgasmic sex.