Rentaro Satomi has blue hair, wears his own Magata High school uniform, wears his own boots and he has brown eyes and in the manga he has blue eyes that are different from the anime. He was a soldier and a agent from the Tendo Civil Security Agency who wields a weapon named the Springfield XD with a black bullet that can penetrate monolith monsters and he was a serious perosn that he can survive without being killed. He has Tendo hand to hand combat while he was fighting with Kagetane Hiruko in a total loss and his arm was demonic while he can charge up his own strength.