The Familiar of Zero: The Maid's Crisis

Siesta is sold to a royal family from out of town, presumably to be a mistress to the head noble. Disgusted by the lack of regard that nobles have for commoners, Saito tries his best to rescue her, but with no avail. As Saito attempts to take on the noble by fighting, Louise and the others arrive just in time to prevent Saito's death. In an act of kindness, Kirche gives up her family treasure to make up for Saito's actions and win Siesta back. Before leaving the manor, Saito catches a glimpse of the family treasure, and is shocked to find that it is in actuality a rather old porno magazine from Earth.