Piero is a ghost boy stunted mentally and physically at 13 years old. He serves as a messenger for the shrine maidens of Hanagumori and was adopted by Tayuki Megumi, the maiden of the Tayuki shrine, so many people address him as Tayuki Piero. His actual age is unknown, but he bears a strange resemblance to a child who went missing from Kiyoka Village during the youkai attacks several hundred years ago.

He has a pet bird named Sol who follows him around and pecks at intruders.