Maou no Ore ga Dorei Elf wo Yome ni Shitanda ga, Dou Medereba Ii?

When the sorcerer Zagan decides to participate in an auction selling the goods of the now dead Archdemon Marchosias, he expects to find items of untold power. What he finds instead is a rare white-haired slave elf named Nephilia, and he immediately spends all his money to purchase her, much to the bewilderment of those around him. However, the secret reason behind Zagan's investment was that he had actually fallen in love with her at first sight.