The third-rate ghost story writer Kumohachi and his assistant, a faceless yokai illustrator named Ari who is a mujina, form an unlikely pair as they investigate mysterious supernatural occurrences throughout Meiji-era Japan. The narrative blends horror with a playful, pop-inflected tone as this mismatched duo delves into folklore, seeking to create the perfect ghost story manga that captures both the adorable and terrifying aspects of the monster world.

The story is set against the backdrop of a Japan undergoing rapid modernization, where the line between the mundane and the supernatural remains blurred. As they pursue their craft, Kumohachi and Ari encounter a world populated by various yokai, while their investigations bring them into contact with real-life historical and literary figures of the period. These include the famous writer and ghost story collector Lafcadio Hearn, the author Tayama Katai, and the folklorist Kunio Yanagita, whose secret stories are woven into the duo's adventures.

Kumohachi, a down-on-his-luck writer sporting a glass eye, provides the narrative drive, while his companion Ari, whose blank face hides a keen perception of the otherworldly, brings these tales to life through illustration. Their dynamic is central to the plot, forming a creative partnership that is both comedic and earnest. The manga is structured around the cases they take on, each chapter typically focusing on a different yokai or urban legend that they must confront and understand. Through these episodes, the narrative explores themes of folklore, the nature of storytelling, and the relationship between humans and the supernatural beings that coexist with them. The story culminates in their effort to compile their experiences into a single volume, a meta-narrative that reflects the manga's own creation.