is a Japanese anime director and producer, and a founding member of the animation studio Gainax. He is best known for directing the film ' (1987) at age 24, directing Mahoromatic (2001), Magical Shopping Arcade Abenobashi (2002), and an episode of Gurren Lagann (2007). Yamaga also wrote the screenplay for Gundam 0080 (1989).
He is portrayed by actor Tsuyoshi Muro in the 2014 TV Drama Aoi Honà  based on the autobiographical manga by his fellow Osaka University of Arts alumnus Kazuhiko Shimamoto. Yamaga himself cameos in Episode 7 of the series, playing the owner of a restaurant where his fictional counterpart faints.