Shiki’s friend who, two years ago, made a promise with Shiki to attend college. He discovers a doll at an exhibition his friend asked him to and falls in love with its flawless craftsmanship. He is so charmed by it that he seeks out the maker, Touko Aozaki, and then finds her residence. With his hopes of attending college with Shiki crushed because of her coma, he drops out of college to work under Touko as an assistant investigator. Touko holds his investigative skills with high-regard because of his ability to find her workplace, an abandoned building hidden to all except those who wish to find it. The male Shiki and the current Shiki call him Cocteau (コクトー, Kokutoo?) due to his last name’s resemblance to Jean Cocteau’s last name, though the current Shiki dislikes it for an unknown reason.
The child time Mikiya is voiced by Eri Kitamura.