Tantei wa mou, Shindeiru. was originally serialized on the Kakuyomu website, and the novel will be published in print form by Media Factory (a division of KADOKAWA) under their MF Bunko J imprint in Japan on November 25, 2019.
Tantei wa mou, Shindeiru. is narrated by voice actress Aoi Yūki.
The story of Tantei wa mou, Shindeiru. follows Kimihiko Kimitsuka, a young man who four years ago became the assistant of a mysterious detective known as “Siesta” on a hijacked airplane.