Sonogo, Yuusha no Sugata o Mita Mono wa Inai The Motion Anime

Hero Aster overthrows the Demon King, but soon after turns into a girl with the help of unknown magic.

Due to the transformation into a girl, Aster loses his heroic abilities,

Aster finds a new job and enjoys his second life.

However, soon a 'perverted demon' appears again in the world, which was secretly created by the Demon King and was supposed to disappear with his death. To satisfy his hunger, he attacks innocent girls. Among them is the former hero Aster...