Struggling writer Momosuke Yamaoka embarks on a quest to gather one hundred ghostly tales in a bid to revive his failing career during the Edo period in Japan. While on his journey, he ventures deep into the mountains and encounters the enigmatic monk Mataichi. Ignoring warnings to retreat, Momosuke witnesses a murder committed by Mataichi and his companions, who specialize in investigating and avenging paranormal wrongdoings. Despite the monk's sinister nature, Momosuke finds himself entangled in their quest for justice, repeatedly intersecting with the trio and questioning the ethics of their actions. As he delves deeper into this shadowy realm, the author navigates a blurred reality where the boundaries between the ordinary and supernatural blur, prompting a profound moral dilemma.