Demon Lord, Retry! (Manga) Volume 3 by Kurone Kanzaki

There's no rest for the wicked, even a not-so-wicked Demon Lord. As Rabbi's hot spring prepares for opening, Akira begins wooing the right nobles and summoning extra assistance - but is it enough to win over the Madame? After all, keeping up operations devours cash and that means grinding away on quests and baddies, even while simultaneously trying to keep overeager adventurer Yukikaze from grinding away as well. You may have to think big to be big, but for Akira, being big enough is definitely not the problem...