Manabu Kaminaga is a Japanese mystery and horror novelist born in 1974 in Yamanashi Prefecture. He initially pursued a career in film direction, attending and graduating from a film school with that goal in mind. However, after his plans for a filmmaking career did not materialize, he worked as a company employee while continuing to write in his spare time. His professional writing career began when he self-published a story titled Akai sekigan, which attracted the interest of a publisher. This led to his official debut in October 2004 with the novel Psychic Detective Yakumo, the first entry in the series that would become his most famous work.

Kaminaga is best known as the original creator of the Psychic Detective Yakumo series. The story follows Saitou Yakumo, a college student born with a red left eye that gives him the ability to see ghosts and spirits. Yakumo believes that spirits are bound to the living world because of unresolved issues, and he works to resolve those issues so they can move on to the afterlife. Alongside a fellow student named Haruka Ozawa, he investigates supernatural mysteries and assists the police with cases involving paranormal elements. The original novel series was published by Nihon Bungeisha with illustrations by Katoh Akatsuki and later by Kadokawa Bunko with cover art by Yasushi Suzuki. The main series ran from 2004 to 2020, comprising twelve volumes. Several side story volumes under the titles SECRET FILES and ANOTHER FILES were also released.

The success of the Psychic Detective Yakumo novels led to multiple adaptations across different media, establishing Kaminaga as an author whose work has significant multimedia reach. The series was adapted into a thirteen-episode live-action television drama that aired on TV Tokyo from March to June 2006. A manga adaptation illustrated by Ritsu Miyako was serialized in Hakusensha's Bessatsu Hana to Yume magazine from 2007 to 2008, compiled into two volumes. A second manga adaptation, illustrated by Suzuka Oda, ran in Kadokawa's Monthly Asuka magazine from 2009 to 2016, spanning fourteen volumes. A thirteen-episode anime television series produced by Bee Train aired on NHK-BS2 from October to December 2010. The franchise has also inspired stage plays. To commemorate the twentieth anniversary of the series in 2025, a new manga adaptation of the Shinrei Tantei Yakumo INITIAL FILE novels was announced, with Suzuka Oda returning as illustrator.

Beyond the Psychic Detective Yakumo franchise, Kaminaga has written numerous other novels and developed story concepts for various manga series. Among these is the four-volume series Conductor, which received a German-language release. His other notable works include the Tenmei Tantei Shingo Sako series, the Kaitou Tantei Yamcat series, and Shadow Conductor. He became a member of the Mystery Writers of Japan in 2009.

Kaminaga's body of work consistently blends mystery, detective fiction, and supernatural horror elements. His stories frequently feature protagonists with unusual abilities or perspectives who work to solve crimes and uncover truths that lie beneath seemingly ordinary surfaces. The themes of resolving past trauma, the connection between the living and the dead, and the pursuit of justice through logical deduction combined with paranormal insight recur throughout his major series. With the Psychic Detective Yakumo novels alone reporting over seven million copies in print, Kaminaga has achieved notable commercial success and established himself as a significant figure in the Japanese mystery and light novel genres, with a career that has successfully expanded into anime, manga, and live-action drama.