The S-Class Dungeon Owner

Being the owner of a dungeon is the best dream a demon could have. So when Succubus Adelaide inherits one from an unknown grandfather, she believes she's set for life. Unfortunately, her inheritance comes with an enormous amount of debt, and she'll have to raise the dungeon's rank from F-class to S-class if she has any hope of paying it back. But all that hard work will be worth it because Adelaide will soon be owning much more than just a dungeon as the mistress of three men who beg for the succubus's attention...!

(Source: Tappytoon)