Ron Kamonohashi

is a Japanese manga series written and illustrated by Akira Amano. It has been serialized in Shueisha's ''Shōnen Jump+'' since October 2020, with its chapters collected into 17 volumes as of June 2025. Shueisha also simultaneously publishes the series in English on the ''Manga Plus'' online platform.

An anime television series adaptation produced by Diomedéa aired from October to December 2023. A second season premiered in October 2024.

Premise

The series focuses on the adventures of Ron Kamonohashi, an eccentric private detective, and Totomaru Isshiki, an unskilled police officer, as they solve crimes together. Five years ago, Ron was the top student at the Detective Training Academy Blue. However, after being found responsible via temporary insanity for a deadly incident known as the "Bloody Field Trip", his detective license was revoked and he was expelled. Unable to fulfill his only love of solving mysteries, Ron has lived in isolation since. When Totomaru seeks his help on a case, the two form a partnership where Totomaru takes the credit for the cases that Ron solves.

Characters

Main characters

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:A sixth-generation descendant of Sherlock Holmes, and a ninth-generation descendant of James Moriarty. His detective license was revoked five years ago following the "Bloody Field Trip", an incident he cannot remember. Whenever he hears a murderer confess their crime, Ron enters an uncontrollable state where he pressures and convinces them to kill themselves.
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:A police detective in the Metropolitan Police Department who gains some renown by taking credit for the cases that Ron solves. Ron calls him by the nickname .
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:Totomaru's boss in the Metropolitan Police. Although usually cold and serious, she has a crush on Ron, whom she thinks is named .
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:A renowned neurosurgeon who is extremely clumsy outside the operating room and is always wearing bandages due to her injuries. She concocts a combination of medicines to suppress Ron's "culprit-killing" syndrome, but there are side effects.
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:A pedantic detective from the Aichi Prefectural Police. He has the highest number of solved cases in the entire country and is an old colleague of Amamiya.
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:A crime reporter who often helps Totomaru and Ron with research and information gathering. She greatly admires Totomaru and dislikes Ron.
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:An American who transferred to Blue Academy three days before the "Bloody Field Trip" and claims to have been Ron's friend, although Ron does not remember him. He is revealed to be an assistant to the Holmes family, specifically to Ron's mother, who views him as an adopted son.

Blue

The in England is the world's most prestigious academy for training detectives.
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:The tracking instructor at Blue, who is sent to investigate whether Ron is violating his detective ban. However, his actual goal is to have Ron help him find his missing brother. Spitz befriends Ron and Totomaru and continues to assist them on various cases.
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:The locked room instructor at Blue and one of less than 10 people in the world who have an S-rank detective license.
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:Fin's bodyguard and a graduate of Blue. He attended the academy at the same time as Ron. He is revealed to be the M. Family's informant at Blue.
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:The anatomy instructor at Blue. He has been a suspect in 15 murder cases, with one of these instances being the reason he was demoted to A-rank detective.
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:The principal of Blue and a friend of Ron's parents. She informs Ron of the M. Family's involvement in the Bloody Field Trip incident, though discretely due to there being an M. Family informant at Blue.
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:The closed circle instructor at Blue.
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:The number one student at Blue, son of a vice-chairmen of the World Detective Alliance, and a descendant of the first principal of Blue.
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:The number two student at Blue, who wears a headband with rabbit ears on it.
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:A top student at Blue, who attends thanks to a scholarship under John Grizzly.
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:A top student at Blue.

M. Family

The , more commonly referred to as the , is a legendary crime syndicate and the archenemy of the Holmes detective family.
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:Milo's uncle, whose real name is .
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:The fourth child of the M. Family who specializes in disguises. After failing at a mission, Milo has an assassin shoot Winter, but then has doctors nurse her back to health as she survives the attack. After recovering, Winter splits from Milo, whom she never forgave for killing their younger sister Alice.
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:The eldest child and head of the M. Family. He killed his younger sister Alice in order to earn that position. After he loses to Ron, Milo is attacked on the orders of the "new boss" of the family. This is later revealed to be Alice, who survived because she tampered with the gun before Milo shot her. "Disappointed" that Milo showed emotion by hugging her and crying after the shooting, Alice plotted to steal the M. Family away from him once she turned 17.
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:The youngest child of the M. Family. Initially believed to be dead, Alice first appears in the series under the guise of , nicknamed "Billy Goji", a top student at Blue who always has various animals on her. She perpetrates a series of murders at Blue, before escaping custody as her true identity is revealed.

World Detective Alliance

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:Director of the Japanese Branch of the World Detective Alliance, an underclassman of Ron at Blue, and the son of Kiku, a police officer and friend of Ron.

Media

Manga

''Ron Kamonohashi: Deranged Detective'', written and illustrated by Akira Amano, began its bi-weekly serialization in Shueisha's online magazine ''Shōnen Jump+'' on October 11, 2020. The series ended its first part on April 30, 2023, with the second part beginning on June 4. The second part is set to end on July 6, 2025. Shueisha has collected its chapters into individual volumes. The first volume was released on February 4, 2021. As of June 4, 2025, seventeen volumes have been released.

The series has been licensed for simultaneous publication in North America as it is released in Japan, with its chapters being digitally launched in English by Shueisha on its ''Manga Plus'' service.

Volumes

Chapters not yet in ''tankōbon'' format

These chapters have yet to be published in a volume.

* 155–166.

Anime

An anime television series adaptation was announced on December 18, 2022. The series is produced by Diomedéa and directed by Shōta Ihata, with scripts written by Wataru Watari, character designs handled by Masakazu Ishikawa, and music composed by Yo Tsuji. The series aired from October 2 to December 25, 2023, on Tokyo MX, AT-X, and other networks. The opening theme song is by Unison Square Garden, while the ending theme song is by .

Following the airing of the final episode, a second season was announced. It aired from October 7 to December 30, 2024. The opening theme song is , by , while the ending theme song is , by Hockrockb.

Crunchyroll streamed the series outside of Asia under the title ''Ron Kamonohashi's Forbidden Deductions''. Medialink licensed the series in South, Southeast Asia, and Oceania (except Australia and New Zealand) and is streaming it on its Ani-One Asia YouTube channel for its Ultra subscribers.

Episodes

=Season 1 (2023)

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=Season 2 (2024)

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Stage play

A stage play adaptation ran from November 1–4, 2024, at the Nippon Seinenkan Hall in Tokyo, and on November 9 and 10 at the Sankei Hall Breeze in Osaka. It was written and directed by Keita Kawajiri, with music composed by Futoshi Arai.

Reception

In June 2021, ''Ron Kamonohashi: Deranged Detective'' was nominated for the seventh Next Manga Awards in the Best Web Manga category and placed 14th out of 50 nominees. The series has been recommended by mystery writers Rintaro Norizuki, Masaki Tsuji and Sako Aizawa, all of whom have topped the ''Kono Mystery ga Sugoi!'' list. In a blurb, Aizawa called the series an "authentic mystery manga for the new era" and praised its fast pace, as well as the tricks and logic used to identify the culprits. Ryoko Fukuda of ''Real Sound'' compared the relationship between Ron and Toto to that of the straight man and funny man roles in comedy, and said she was looking forward to how the "pop, fast-paced story" would develop.

Notes

References

External links

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{{Diomedéa

Anime and manga based on Sherlock Holmes
Anime series based on manga
AT-X (TV network) original programming
Crunchyroll anime
Detective anime and manga
Diomedéa
Japanese webcomics
Medialink
Mystery anime and manga
Plays based on comics
Shōnen manga
Shueisha manga
Webcomics in print