Reze appears to be a young woman or girl, and is of slender build. She has shoulder-length purple hair and emerald-green eyes. She is shown to be prone to blushing heavily. she is seen wearing a choker in order to conceal the grenade pin in her neck, which she uses to transform. She wears a sleeveless white button-up blouse neatly tucked into black high-waisted shorts with subtle side slits. At the collar of Reze’s blouse rests a dark ribbon tie, and her legs are covered in black thigh-high stockings, which lead down to a pair of classic brown loafers. As the Bomb Hybrid, Reze's transformation is that of an atomic bomb, mostly reminiscent of the Fat Man atomic bomb which exploded over Nagasaki in the last moments of the Second World War. She had the atomic bomb as her head and her teeth are always visible and are notably sharp and angular. Bomb fuses cover her arms like sleeves while also making up a portion of her apron along with sticks of dynamite. Reze initially appears to be a kind and gentle girl who has a crush on Denji soon after meeting him, taking interest in him at first sight and was portrayed to be as somewhat enthusiastic, laughs at his jokes and isn't afraid to get close and intimate with him. Reze is also shown to be a bit of a tantalizer, teasing Denji on some occasions, While also displaying a rather sympathetic side to her. This was later revealed to be just a façade in order to get her closer to Denji; even her seemingly true reactions like blushing in his presence were results of a harsh military training that Reze was subjected to from a young age. However, Reze had shown mercy towards Denji despite her mission, Despite her fake crush on Denji, Reze somewhat reciprocated his feelings towards her, and empathized with him since they had both never been to school before. Although using more manipulative type of fighting, she seems to not enjoy killing or harming others and prefers to avoid it, unless it's necessary for her mission. She shows little respect towards the owner of the café she works at.