Yuusha no Kawari ni Maou Toubatsu Shitara Tegara wo Yokodoroi Saremashita

As a member of the hero's party, Arga hid his identity and was on a journey to subjugate the King of the demon with the hero. At last the party chased the demon king, and Arga brought him down. However, the hero insists that he was the one who killed the demon king, and then charges Arga with an innocent sin and banishes him from the Imperial...