Denji is a teenage boy with blonde and scruffy hair. He has yellow-brown eyes and bags underneath, resulting in a dazed and tired expression. His teeth are noticeably sharp and angular. Due to malnutrition in his childhood, he has a scrawny build with protruding ribs, and due to the stress of what he did for a living, he’s often mistaken for being older than he actually is. Once he became a devil-hybrid. He came across a person named Makima and started to develop feelings for her.