It was announced after the final episode of Gate: Jieitai Kanochi nite, Kaku Tatakaeri that the series will broadcast in split cours, with the second half to premiere in January 2016. According to a preview released, it will cover the Fire Dragon Arc.
The first season aired from July 4, 2015, to September 19, 2015, for a course of 12 episodes. It adapts the light novel written by Takumi Yanai with illustrations done by Kurojishi and Daisuke Izuka. The light novel consisted of five volumes that published from April 12, 2010, to December 22, 2011.