Kohtaro Kuga, standing next to Sayo Yuuki in her Sazae form, as they appear in Shikigami no Shiro III.
Kohtaro Kuga (玖珂 光太郎) is the main protagonist of the Shikigami no Shiro series, appearing in every installment in the series to date. His shikigami was once a woman named Sazae, but in Shikigami No Shiro III, his shikigami is now Sayo Yuuki.