Maou no Ore ga Dorei Elf wo Yome ni Shitanda ga, Dou Medereba Ii? / 魔王の俺が奴隷エルフを嫁にしたんだが、どう愛でればいい？

The young but feared sorcerer Zagan is a candidate to become a member of the 13 Archdemons—a group of the strongest sorcerers in the world—following the death of their eldest member, Marchosias. When attending the deceased Archdemon's estate auction, Zagan finds something he did not expect: love at first sight. The sorcerer impulsively spends all his money to take Nephelia, a rare elf slave, back to his castle. Given the girl's mysterious and troubling past, there is a lot for Zagan to uncover about his new companion. However, Zagan's lack of experience with the unfamiliar feeling of love leads to many awkward moments between him and Nephelia, whom he calls by the nickname "Nephy." As the two grow closer and get more comfortable around each other, it becomes increasingly evident that Nephy's feelings might not be so different from Zagan's. ...