Hiroto Amagiwa serves as the Major and Commander of the starship Bilkis in his series. At only sixteen years old, he holds a position of immense responsibility, having received an elite education from infancy that was specifically tailored to his genetic makeup. This upbringing was designed to groom him for his role as a future leader of humanity, placing him in a command position at a remarkably young age.

In terms of his physical appearance, Hiroto is depicted as an adolescent male with brown eyes and blue hair that reaches his shoulders. His demeanor is defined by calmness and composure, exhibiting a precise and reliable judgment ability that serves him well as a military commander. This outward behavior, however, often leads the majority of his crew to perceive him as an emotionless robot who simply gives orders. Despite this perception, Hiroto considers himself to be a normal person with normal sensitivities, suggesting a depth of feeling that he does not readily display to those under his command.

No reliable direct information exists regarding his motivations, specific role in the story, key relationships with other characters, personal development throughout the narrative, or notable abilities beyond his command skills.