Because they are wealthy and above the law, the titular "tarantula" murders without a warrant, and she collaborates with her brother, who is madly in love with her. Kyoshiro, the masterless wandering samurai with nothing to lose and no scruples in any case, can easily reprimand even the most powerful of people. As a result, despite the fact that he possesses vast streaks of villainy all his own, he is regarded as a champion of the people by default.