A schoolgirl on her way home is approached with a sudden proposal: "Could you barge into your father's bath and seduce him with a 'close-contact bath mission'?" The prank's premise is simple: if the father can resist having sex with his daughter, he wins 1 million yen! Before the challenge, the daughter confidently says, "There's no way he'd get excited by me!" However, when she presses her unexpectedly well-developed body against him, the father's cock instantly goes full erect! Unable to contain his arousal, will the father secretly engage in forbidden incest creampie sex with his daughter behind the mother's back!?