A second-year student at Magata High School. He is also an employee of the Tendo Civil Security Agency operated by Kisara Tendo. Alongside his Initiator partner, Enju, he stands against the Gastrea, parasitic organisms that defy human imagination.

One of the 'Cursed Children' who carry the Gastrea virus in their bodies. A 10-year-old girl with superhuman abilities and a somewhat precocious personality. She follows her partner, Rentaro Satomi, like a lover and views the well-endowed Kisara Tendo as a romantic rival. Her Model type is Rabbit, making kicks her primary weapon.

The youngest daughter of the prestigious Tendo family, she left home due to certain circumstances and now lives alone. Despite being a student from a noble background, she manages the Tendo Civil Security Agency while struggling with extreme poverty. She is the girl Rentaro has feelings for. A master of the Tendo Style Battojutsu, she seeks revenge for her parents.

A girl Rentaro rescued when she was being harassed by delinquents. She appears to be nocturnal, often seen in a dazed state during the day while popping pills. She becomes entwined with Rentaro through a strange twist of fate.