After a tragic accident, Keisuke, mild-mannered teacher by day and rapist vigilante by night, and his Uncle Shotoku discover a conspiracy within a Tokyo hospital to sell children's organs to the Hong Kong mafia. Keisuke must use his expertise to unravel the corruption and right wrongs through penetration!

In this first installment of the series - we are introduced to Keisuke: mild mannered school-teacher by day - avenging angel of rape by night - and his goofy Uncle, who together run Rapeman Services. Their "services" are called-upon by a nightclub owner who tells a sob story about having her boyfriend, a current political candidate, stolen by his secretary, and asks Rapeman to "take care of her" as an act of revenge. This is done per the nightclub owner's request - but we soon find that the story was just a cover to cause a bigger scandal that involves rival a seedy rival politician and the Yakuza...

After an assignment-gone-wrong, Keisuke decides to quit Rapeman services, leaving Uncle to take his place. All the while, they are targeted by one of their previous victims, who has hired a Rapeman look-a-like to tarnish our hero's good name and attack Keisuke's closest friends. Has Rapeman finally met his match? Tune in to find out! Same rape time, same rape station.