Based on the erotic game by Waffle.

Lute is a fresh graduate of the Royal Knights Academy. Although he does not much mind it himself, he is regularly looked upon in contempt for having graduated at the bottom of his class. Almost immediately after graduation, Lute is assigned to Boan, the poorest district of the realm. Rumors have it that Boan is also the place where surviving devils have taken refuge and continue to work evil.