忘八者，即在吉原一代从事色情业，将“孝、悌、忠、信、礼、义、廉、耻”这为人八德抛弃、被世人看作畜牲和无赖的人。 　　江户时代的刽子手明日死能（丹波哲郎 饰）为官府追赶，幸得吉原的忘八和妓女们相助，方得脱险。吉原的巨头大门四郎兵卫（远藤辰雄 饰）赏识明日的才能，力邀其入伙，协助其剿灭吉原之外的私娼寓所，以独霸当地色情业。此举令私娼业者闻风丧胆，为对抗大门，他们延请黑锹忍者小角（内田良平 饰）刺杀明日。双方的战争一触即发……In PORNO PERIOD DRAMA, Tetsuro Tanba plays a nihilistic ronin who faces down the "Clan of the Forgotten Eight", who got their name because they lost all their basic emotions like conscience, gratitude, loyalty, shame etc. With his sword Onibouchou (literally: Ogre's Kitchen Knife!) Tanba's character hacks into their ranks in ways that has limbs and severed heads fly everywhere and the blood flows in rivers! On his way, he only stops to take every woman he meets, forcefully if need be!