Koike often urged his students to create well-thought out, interesting characters, and this influence would greatly impact Rumiko Takahashi's works throughout her career.
Kazuo Koike tvang ofte sine elever til at skabe spændende, veludtænkte karakterer, og hans indflydelse kom i stor grad til at præge Rumiko Takahashis manga-serier igennem hele hendes karriere.