Hiroshi Mori was born on December 7, 1957, in Aichi Prefecture, Japan. Before beginning his career as a writer, he worked as an engineer and researcher, holding positions as an associate professor at Nagoya University where he specialized in rheology, the study of the flow of matter. He resigned from his academic post in 2005 to dedicate himself fully to writing. His background as a scientist and his lifelong interest in model crafting, particularly radio-controlled airplanes, have deeply influenced his creative work. From a young age, Mori was also passionate about manga; he joined a manga club in university, self-published under the pen name Mori Muku, and met his wife, illustrator Subaru Sasaki, through this shared interest. He has cited shōjo manga artist Moto Hagio as a profound inspiration.

Mori made his literary debut in 1996 with the mystery novel The Perfect Insider, which won the first Mephisto Prize. This work launched his long-running S&M series, which features mystery plots often intertwined with scientific and mathematical concepts, a style sometimes referred to as "rikei mystery" or science mystery. While best known for his mystery novels, Mori has written extensively across genres, including science fiction, romance, essays, and children's books. He is known for being a prolific and punctual writer, reportedly completing his first novel in a single week while still working as a university professor.

Among his extensive bibliography, the novel series The Sky Crawlers stands as his most significant contribution to anime and manga media. The series consists of six books published by Chuokoron-Shinsha between June 2001 and June 2008, with illustrations by manga artist Kenji Tsuruta. The publishing order was intentionally non-chronological, with the first book released being meant as the final installment in the story's timeline, a decision Mori made to emphasize that the narrative did not need to be read in order. The series is set in an alternate historical period and follows a group of young fighter pilots, known as Kildren, who exist eternally in adolescence unless killed in combat.

The first novel in the series was adapted into an anime film, also titled The Sky Crawlers, directed by Mamoru Oshii. The film was produced by Production I.G, written by Chihiro Itō, and released by Warner Bros. Japan in theaters on August 2, 2008. Mori stated that he considered this work the most difficult of his to adapt but gave his consent for the film upon learning of Oshii's involvement as director.

The Sky Crawlers franchise also expanded into other media. A video game, The Sky Crawlers: Innocent Aces, was developed for the Wii by Namco Bandai's Project Aces team. Released in Japan in October 2008, its plot serves as a prequel to the anime film. Additionally, a manga series titled Sky Crawlers: Innocent Aces, based on the game and illustrated by Yūho Ueji, was serialized in Monthly Comic Blade starting in November 2008 and later compiled into two volumes.

The core themes of Mori's work often reflect his background and interests. His writing is noted for blending scientific and engineering concepts with narrative, a trait evident in his "rikei mystery" works. His lifelong passion for aviation and model aircraft is a central element in The Sky Crawlers series. His early engagement with manga as a creator and his continued appreciation for the medium inform his artistic identity, even as he is primarily known as a novelist. The significant multimedia adaptation of The Sky Crawlers into a major anime film, a video game, and a manga series represents a key point of connection between his original literary creations and the broader world of anime and manga.