Denji is a teenage boy with blond 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. he has a  a chainsaw cord in the middle of his sternum

If his chainsaw cord is pulled his head will morph into a demonic, mechanical shape with long, jagged fangs and a chainsaw handle on the back. Large chainsaws will emerge from his forehead, arms and legs, he is able to retract and extract any of them at will.