Reze is a young girl who met Denji in a phone cabin. She works at a local café and is a kind and gentle girl who seems to have a crush on Denji soon after meeting him. She laughs at his jokes and isn't afraid to get close to and intimate with him.

‌‌‌‌‌‌‌‌She is secretly the Bomb Devil hybrid, owned by the Soviet Union and allied to the Gun Devil. Her true personality is manipulative and brutal, as she is shown killing many Devil Hunters without care or mercy. She does, however, not enjoy killing and prefers to avoid it, unless necessary for her mission. Her objective is to retrieve the Chainsaw Heart from Denji, but the feelings she developed for him quickly made things more complicated.