Remote Parasite: Gao no Nai Oni ga Goku wo Kurau

At the suggestion of his editor, struggling manga artist Inuma is tasked with adapting a psychological horror work by the immensely popular manga artist Narita Hikaru into a comic. Inuma is impressed by the work's horrifying yet fascinating nature, and begins drawing with high hopes that it will undoubtedly become a masterpiece. However, from that day on, a series of disturbing and disgusting events begin to occur around him...

(Source: Akita Shoten, translated)