A prank plan where a father, during his daughter's school commute, suddenly proposes a "close bath mission" to her, asking, "Would you be tempted to join me in the bath while your dad is bathing?" The challenge: if the father can resist having sex with his daughter, he wins 1 million yen! Despite the daughter's confidence before the challenge, "There's no way I'd excite my own daughter!", upon close contact with her unexpectedly developed body, the father's... fully erect! Will the uncontrollably aroused father secretly engage in forbidden incestuous sex with his daughter without the mother's knowledge?
