This studio-as-hospital approach was allegedly invented by Mashimo during his prolonged stay in an intensive care unit (after a severe skiing accident) and has been Bee Train's official strategy ever since.

[4] The first projects published by the studio in 1999 were anime adaptations of video game franchises popular in Japan: PoPoLoCrois, Arc the Lad, Wild Arms: Twilight Venom, and Medabots.

Later, Bandai Visual joined forces with Bee Train to produce an anime OVA based on the famous .hack video game series.

[4] After Noir had become widely successful in Japan, France, the United States, Germany, and other Western countries, the second series, Madlax, was produced in 2004 and the third, El Cazador de la Bruja,[5] went on air in April 2007.

Although the "girls-with-guns" series are considered Bee Train's and, particularly, Mashimo's signature works, the original idea belonged to their common executive producer Shigeru Kitayama.

For example, this list includes Hōko Kuwashima (Kirika Yuumura in Noir, Margaret Burton in Madlax), Aya Hisakawa (Chloe, Limelda Jorg, Jodie Hayward in El Cazador de la Bruja), and Kaori Nazuka (Subaru in .hack//Sign, Shino in .hack//Roots).

Kajiura has provided music for Sign, Liminality, Madlax (as part of FictionJunction Yuuka), Tsubasa Chronicle, and recently El Cazador de la Bruja.