An acquaintance of both Tachibana Yoshiaki and his elder brother, who works as a local news reporter for a major Tokyo newspaper company. Naoe met him eight years ago (when Naoe was 22) during a case involving onryou turmoil precipitated by the sinking of a mountain village caused by a large dam construction project. Sonoda made his name by reporting on corruption by the Ministry of Construction in the same project.
Naoe goes to him after Takaya's disappearance as an effort to establish an information network of his own (independent of Uesugi's information apparatus).
