The protagonist, Watanabe, can distinguish genuine paper from fakes and teams up with model maker Doi to investigate a case tied to paper and scale models. The appeal lies in how expertise about paper and craftsmanship becomes integral to the shape of the mystery itself.

The paper already knows the truth behind the case.

During a school festival, a strangled body is found in a haunted house, and the case is narrowed down through careful reconstruction of the timeline. This is a logical school-set mystery focused on the instant when a ghost act turns into a real murder.

When did the ghost on stage become a real corpse?

At Yurigahara High School, a first-year student named Yuriko is drawn into a series of disturbing events tied to the school legend of the "Yuriko-sama." The novel blends urban legend, horror, and murder into a tense school mystery.

Only one girl can become Yuriko-sama. If there are two, one must disappear.

An introverted writer and his childhood friend travel through Kyushu tracing a new theory that connects kappa legends with hidden Christian history. The novel gradually turns local folklore and memory into a larger historical mystery.

The secret behind a kappa’s hand overturns historical common sense.

The story begins with an attack on an elementary school in Osaka and follows a police officer named Natsuki as he investigates unnatural murders caused by an invisible giant paper dog. It is a dark horror-suspense novel centered on events beyond scientific explanation.

An invisible monster is devouring the city.