TV-Series
Description
Momosuke Yamaoka begins his career writing children's riddle books but grows dissatisfied, aspiring instead to compile an anthology of 100 ghost stories. He traverses Edo-period Japan researching supernatural legends for this collection. During his travels, he encounters the Ongyou—a trio of supernatural beings named Mataichi, Ogin, and Nagamimi—who investigate paranormal incidents and punish those guilty of grave sins.

Initially idealistic and naive, Momosuke frequently observes the Ongyou delivering retributive justice, a process that exposes dark truths behind folk legends and executes perpetrators. Fascinated by their mission, he repeatedly requests to join them, only to face consistent rejection and warnings to keep his distance for safety. Despite this, he persistently involves himself in their cases as an observer and occasional participant. His encounters with the Ongyou and exposure to profound human depravity—including infanticide, incest, and mass murder—gradually erode his innocence, inflicting significant psychological strain as he confronts the moral ambiguities of the Ongyou's actions and humanity's inherent darkness.

His relationship with the Ongyou evolves: Mataichi, their leader, addresses him as "Author" and occasionally provides exposition; Ogin exhibits a flirtatious yet protective attitude towards him, initially perceiving his naivety as weakness; Nagamimi often tries to dissuade his interference. An overarching narrative involves Kyogoku Tei, the Ongyou's superior, who first orders Momosuke's elimination but later spares him for unknown reasons.

Physically depicted as clumsy and accident-prone, Momosuke's wide-eyed expressions reflect his early idealism. He functions as an "action survivor," navigating perilous situations through intellect despite lacking supernatural abilities. In the series' climax, he intervenes during a confrontation with Kyogoku Tei, contributing to the antagonist's defeat. Though the Ongyou seemingly perish, Momosuke remains hopeful of their survival. He completes his book of 100 stories, symbolizing his journey through darkness while retaining a measure of optimism.

Through these experiences, he transforms from a wide-eyed idealist into a more cynical yet resilient figure, marked by trauma yet unbroken. He becomes the sole human witness to both the Ongyou's activities and the horrors they confront.