A clinical psychologist and mental health counselor. 36-year-old male. 177cm. A highly knowledgeable and calm man. He has light curly hair and wears a brown jacket. He pursued psychology for criminals and those in rehabilitation after his lover committed a crime and chose death. Currently, he has deep ties with the police and works at a national prison as a civil servant. Many of the criminals he handles are serving heavy sentences, and he also listens to those on life imprisonment or death row. Many people feel disgusted by his method of never denying the criminal and maintaining a gentle conversation; he has been attacked in tabloids and even punched by victims. Some police officers also think ill of him. However, Furuya himself has a strong core and does not mind these things at all. This attitude is sometimes seen as him just going at his own pace. He has a very broad range of knowledge, including philosophy, physics, folklore, and quantum mechanics. He has a wide repertoire and sometimes uses game theory, psychological experiments, and paradoxes in conversation. He is not misled by a client's attributes or public image, but carefully picks up and understands the movement of the other person's feelings. His job is to ensure the counseling session becomes a safe zone for the other party, supporting them so they can relax and focus on their prison duties. He does not consider it his job to force reflection or rehabilitation. He does not look down on the other person, picking up on points of empathy while dissolving their defenses and tension. "I believe no one is born crazy. It's not just about grudges or hatred. Even a perpetrator or a criminal is someone who might have been saved by medical art."

33-year-old male. 174cm. A police officer in charge of assisting Furuya. He records and monitors the counseling sessions. He was initially skeptical of Furuya's work, but is now gradually changing his mind. He has a very strong sense of justice and puts the feelings of the victims first. He is the type to directly express discomfort or dissatisfaction. While he understands intellectually that there are harsh realities and circumstances on the perpetrator's side, he believes that absolute justice exists somewhere. When he was working at a police box in the past, he responded to a report of a suspicious person but failed to arrive in time, resulting in the death of a young man. Since then, he has developed a personality that never compromises with himself.