The Detective Is Already Dead

The Detective Is Already Dead (Japanese: 探偵はもう、死んでいる。, Hepburn: Tantei wa Mō, Shinde Iru.) is a Japanese light novel series written by Nigojū and illustrated by Umibōzu. Media Factory have published the series since November 2019 under their MF Bunko J imprint. A manga adaptation with art by Mugiko has been serialized in Media Factory's seinen manga magazine Monthly Comic Alive since May 2020. Both the light novel and manga are licensed in North America by Yen Press. An anime television series adaptation by ENGI aired from July to September 2021. A second season has been announced.
Ever since he was a child, Kimihiko Kimizuka has attracted trouble. According to him, he was born with a condition that naturally attracts him to troublesome situations, such as being forced to join a flash mob while taking a leisurely walk, accidentally stumbling across an underworld transaction between drug dealers, and being at the site of crime scenes often enough to sometimes be considered a suspect.
One particular day in his third year of junior high, he was kidnapped and forced to carry a suitcase onto an international flight; on that flight, he met Siesta, a beautiful young woman who proclaims herself to be a "legendary detective". Forcefully made into her sidekick, Kimihiko helped her stop the plane from being hijacked, but not before Kimihiko discovered the existence of underworld organizations. After being constantly pestered, Kimihiko agrees to be Siesta's sidekick and for three years, they worked together, finding and solving an innumerable number of cases.
Now in his last year of senior high, Kimihiko is once again confronted by the ghosts of the past as he tries to solve new cases that fall into his lap. He is extremely bothered by the fact that he is called a detective; after all, the detective is already dead.
The idea of The Detective Is Already Dead started from a random sentence the author, Nigojū, thought of one day. The sentence was "Is there a detective on the plane?", and later became the first sentence of the story.
The series is written by Nigojū and illustrated by Umibōzu. Media Factory has published twelve volumes since November 2019 under their MF Bunko J imprint. It is licensed in North America by Yen Press.
Its spin-off Nagisa Natsunagi Still Wants to Be a High School Girl. (夏凪渚はまだ、女子高生でいたい。, Natsunagi Nagisa wa Mada, Joshikōsei de Itai.) is written by Shusui Tsukimi, illustrated by Hanekoto, and supervised by Nigojū. Media Factory has published two volumes since August 2023 under their MF Bunko J imprint. On February 28, 2025, Yen Press announced they had licensed the spin-off series.
Another spin-off Charlotte wa Tada, Jiken wo Tokitai. (シャーロットはただ、事件を解きたい。, "Charlotte Just Wants Solve Cases.") is written by Hinachihoko, illustrated by Minori Chigusa, and supervised by Nigojū. Media Factory published the novel in May 2024 under their MF Bunko J imprint.
Another spin-off Saikawa Yui wa demo, aidoru de iru. (斎川唯はでも、アイドルでいる。, "But Yui Saikawa is still an idol.") is written by Shao Senlin, illustrated by Almic, and supervised by Nigojū. Media Factory published the novel in August 2024 under their MF Bunko J imprint.
A manga adaptation by Mugiko was serialized in Media Factory's seinen manga magazine Monthly Comic Alive from May 27, 2020 to October 27, 2023. It has been collected in six tankōbon volumes so far. Yen Press also licensed the manga adaptation. The manga series covers Vol. 1 and Vol. 3 of the novel series.
A second manga adaptation by Poni titled The Detective Is Already Dead: The Lost Memory (探偵はもう、死んでいる。-the lost memory-, Tantei wa Mō, Shinde Iru. -The Lost Memory-) was serialized in Monthly Comic Alive from January 27, 2021 to September 27, 2022. It has been collected in four tankōbon volumes. The manga series covers Vol. 2 of the novel series.
Its spin-off Toaru Meitantei to Joshū no Love Com-deki Nichijō (とある名探偵と助手のラブコメ的日常), illustrated by Moyashi Itame, has been collected in two volumes so far.
An art book Tantei wa mō, shinde iru. Umi bōzu ātowākusu (探偵はもう、死んでいる。 うみぼうずアートワークス, The detective is already dead. Umibōzu Artworks) is published by Kadokawa.
The 12-episode anime television series adaptation was announced on January 20, 2021. The series is animated by ENGI and directed by Manabu Kurihara, with Deko Akao handling the series' scripts, and Yōsuke Itō designing the characters. Yuuyu, Naoki Tani, and Tatsuya Yano composed the series' music. It aired from July 4 to September 19, 2021 on AT-X and other channels, with the first episode airing as a one-hour special. Mary × jon-Yakitory performed the opening theme song, "Koko de Ikiteru." (ここで生きてる) (lit. "I Am Alive Right Here"), while Kagura Nana performed the ending theme song, "Kodō" (鼓動) (lit. "Heartbeat"). Funimation licensed the series outside of Asia. Following Sony's acquisition of Crunchyroll, the series was moved to Crunchyroll. Muse Communication licensed the series in South and Southeast Asia, and streams the series on its YouTube channel (has been removed), iQIYI, and Bilibili and aired on Animax Asia.
It was announced that the VTubers Shirakami Fubuki and Natsuiro Matsuri of Hololive will have a cameo in the third episode of the anime. On July 14, 2021, it was announced that the anime would receive a German dub with the first dubbed episode airing on July 18 the same year. On October 2, 2021, Funimation announced that the series would receive an English dub, which premiered the following day.
On July 24, 2022, it was announced that the series would be receiving a second season.
The first part of Ep.1, Ep.2 to Ep. 4, Ep. 10, and part of Ep. 11 to Ep. 12 cover the story of Vol.1 of the light novel series. The second part of Ep.1, Ep.5 to Ep.9, and part of Ep. 11 to Ep. 12 cover Vol.2 of the series.
The light novel series won the 15th MF Bunko J newcomer award in 2019.
The light novel series placed third and first in July and August 2021 respectively on the Oricon monthly light novel chart.
As of July 2022, the series has 1 million copies in circulation.