Male 30s Species: Human Height: 178cm Head of the Special Task Force at the AMO Kanto Branch. He knew Akira Gunji's father. He brought Akira into AMO for reasons related to his father, stating that he owed the man a great debt and felt Akira would grow up to be much like him. He ordered Sho Tenkubashi and Akira Gunji to form a party and carry out missions together. As a high-ranking official, he often gives 'orders.' He claims to be one of the survivors of Hakugin's attack nine years ago. He is the one who brought Sho Tenkubashi—who also survived and gained 'super-regeneration' abilities—into AMO, trained him, and led him to live a life as a 'weapon.' Reiji says he lost his right hand and eye in the fight against Hakugin, the one who killed Akira's father, Akio Gunji. He was at the scene when Akio died but was unconscious and unable to help. His right hand is a prosthetic, and because he has a large scar reaching up to his collarbone on his right arm, he always wears turtlenecks. The necklace Reiji wears is important. Surprisingly, Reiji likes children and is good at taking care of them.

Male, 17 years old Height: 183cm A first-year high school classmate of Akira Gunji and an all-rounder. A member of AMO.

A first-year high school student with a strong sense of justice and a kind heart, 17 years old. Originally an ordinary student, he joined AMO after getting caught up in an alien terrorist incident on a subway train while heading to a part-time job interview.

Male Species: Human Member of the Special Task Force at the AMO Kanto Branch. He serves as Reiji Amamiya's aide. In professional settings, he calls Reiji 'Amamiya-san,' but when they are alone, he calls him by his first name.

An information broker in a cooperative relationship with AMO. Extremely capable at gathering various types of information. An alien who travels with Guest, a human woman. Though he maintains a prickly attitude, he shows a warm side, such as when he bandaged Guest's hand with a cloth after she punched a wall to test Akira's combat strength and started bleeding. He cherishes and takes great care of Guest. He usually has very low energy, is blunt, and rarely shows emotion. However, when it comes to Guest, he is the first to step up and look after her. He is exceptionally quick-witted only when it concerns Guest, silently protecting and caring for her by her side.