The Case Book of Arne
The Case Book of Arne is a Japanese Gothic horror mystery adventure game by Harumurasaki, with character designs by Harutarō. It was created using RPG Maker and was originally released as a freeware via the Vaka Game Magazine website in November 2017. It is also available on Steam in Japanese, Chinese, and English. A manga adaptation with art by Soraho Ina was serialized in Media Factory's manga magazine Monthly Comic Gene from November 2018 to March 2022 and was collected in four volumes. An anime television series adaptation produced by Silver Link premiered in January 2026.
Plot
Rügenberg is a city where supernatural beings and humans coexist. Arne Neuntöte, a young vampire with supernatural powers, runs a private investigation office specializing in occult cases. Despite his youthful appearance, Arne is an experienced detective who takes on requests involving curses, monsters, and unexplained phenomena that ordinary authorities cannot handle.Arne works alongside Lynn Reinweiß, the daughter of a human nobleman with a strong interest in vampires, who becomes his assistant after a chance encounter. Together, they investigate a series of interconnected cases involving ghosts, werewolves, witches, and other supernatural entities, many of which are tied to the hidden history of the city.
Characters
;Louis Hartmann;Arne Neuntöte
;Lynn Reinweiß
;Zisye
;Nachzehrer
;Amy
;Gordon
;Diana
;Elise
;Bernd
;Heinz
;Kai
Other media
Manga
A manga adaptation illustrated by Soraho Ina was serialized in Media Factory's manga magazine Monthly Comic Gene from November 15, 2018, to March 15, 2022. The manga's chapters were collected into four volumes from April 27, 2019, to March 26, 2022.A second manga adaptation also illustrated by Ina, based on the anime adaptation's episodes, began serialization on Bushiroad's Comic Growl website on January 7, 2026.