Read Hisshou Dungeon Unei Houhou Manga:
One day in a sunny leisure day, a woman visited my house and asked me if I’m interested in managing a dungeon along with support from a goddess. But of course, I refused. Eh? I shouldn’t ignore a person in trouble, moreover if it’s a beautiful woman? No way, that’s too bothersome and why do I have to do that? I’m perfectly satisfied with my comfortable life now, thro more.. wing it away is just overly stupid... Sigh, fine. So I just go to another world, become a dungeon master, manage a dungeon, and deal with a mana circulation problem? Understood, but how to do it? Let me show you how...