A non-human entity possessing the appearance and memories of the Hikaru who died in the mountains. While he purely continues to learn in order to understand humans and cherishes Yoshiki above all else, he possesses non-human values and instincts, occasionally performing terrifying acts with total composure. He can see the mountain's curse, the 'Defilement'.

Hikaru's childhood friend. The only person who knows better than anyone that the 'returned Hikaru' is different from before. While struggling, he tries to accept this existence, carrying intense guilt and loneliness. He has a kind personality but is being driven to a psychological breaking point. He can see the Defilement.

Born with strong spiritual sensitivity, she can sense non-human entities. She has a strong sense of responsibility to protect her friends. Calm and realistic. She can sense the Defilement.

A female student often seen with Asako. She has the perspective of a very ordinary high schooler, interested in gossip and school life. She does not notice the anomalies. Childhood friends with Asako. She cannot see the Defilement.

A friend of Yoshiki and the others who doesn't notice subtle inconsistencies, serving as the mood-maker in class. A cheerful, caring, and friendly guy with a shaved head who acts as the class clown. He cannot see the Defilement.

Asako's mother. She possesses the power to see aberrations and Defilement invisible to ordinary people, and understands the danger better than anyone due to past experiences. A gentle and caring woman who acts to protect her daughter and those around her. She can see the Defilement.

A spiritual countermeasure specialist and investigator dispatched to the village by a company. Aloof and elusive, he travels with a hamster. Well-versed in Defilement and the supernatural, he is investigating Hikaru's true nature, leading Yoshiki and Hikaru to be wary of him. He speaks in standard dialect.