Denji is a teenage boy with scruffy blond 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. Denji is both brash and naïve as a result of being unable to have a formal education.