Sōsuke Mitsuba

A ghost who was causing trouble at the elevator entrance.

He had an androgynous face, and Kou often described him as having a feminine face. His right eye was hidden by his bangs. He was cheeky by nature and had a hobby of taking photos. He was particular about his photos, only taking pictures of things he liked or considered valuable.

After dying in an accident, he became known among the students as the "ghost at the elevator entrance," a rumor that started because he was calling out to someone he thought was his friend (he himself told this to Kou). Eventually, he was caught by Kou. He told Kou that his regret was tied to his inability to take photos, and Kou offered to help him resolve his regrets, leading them to become close friends. However, he was turned into a monstrous apparition known as the "Broken Neck Ghost" by Tsukasa and others, and began to attack others.

He was eventually eradicated by Hanako's hand, but Tsukasa placed a part of his soul that he had extracted into a spirit body created from a collection of low-level spirits, allowing him to remain in this world. Later, he inherits the power of the Third Wonder, "Kagami Jigoku." However, "Sōsuke Mitsuba" as a person and "Mitsuba" as the Third Wonder are entirely different entities.

Currently, he is with Tsukasa and the others. He has lost his memories and does not remember Kou.