Yowai 5000-nen no Soushoku Dragon, Iwarenaki Jaryuu Nintei

The old herbivorous dragon, who gets mistaken for an evil dragon, and Reiko, a young girl with miraculous powers, arrive in a totally new country, Asgar, where the herbivorous dragon keeps taking the blame when he gets caught up in an elaborate conspiracy. Even though he just wants to live a peaceful life, the herbivorous dragon is continuously getting stuck in his role as the evil dragon and walks further and further down the road towards overthrowing the demon king.