The Rapeman (1993)

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...