A-1 Pictures (株式会社A-1 Pictures) is a Japanese animation studio founded by ex-Sunrise producer Iwata Mikihiro and it is a subsidiary of Sony Music Entertainment Japan’s anime production firm Aniplex.

The studio was established by SMEJ’s animation production division, Aniplex, on May 9, 2005, to animate its anime series and productions. In 2006, it co-produced the original production Zenmai Zamurai, and in October of the same year, established a studio in Asagaya. In the following year, 2007, the studio produced its first series, Ookiku Furikabutte.

Originally established to oversee the production of only a few of Aniplex’s family-oriented series, the studio has since grown and expanded as a full-fledged studio involved in the production of a wide range of media and anime productions and other activities, which it has overseen.
*wikipedia