Nezumi, also known as Rat, is a central character in the anime series No.6. A mysterious and intelligent young man, Nezumi is known for his cunning and resourcefulness. Having escaped from the oppressive city-state of No.6, he lives in the slums outside its walls. He saves the protagonist, Shion, from certain death and they develop a complex relationship. Nezumi is driven by a deep-seated hatred for No.6 due to past traumas, and he plays a pivotal role in uncovering the city's dark secrets. His character blends charm with an enigmatic aura, making him a key figure in the narrative.