The Other World's Books Depend on the Bean Counter, Vol. 4 by Yatsuki Wakatsu

So it’s been a bit, but an accountant guy somehow went down a portalhole and into a fantasy world. Once he got there, the first thing he asked for was a job. That’s how Kondou’s career in the Romany Kingdom’s Accounting Department began and part of the reason a stunning knight captain stumbled upon a bean counter in distress. Venturing to the depths of a dangerous forest on a quest to clear the miasma is the exact opposite of what Kondou’s knight in shining armor wants him to do. However, our intrepid bean counter is a man with a plan, so venture forth he does—much to the captain’s dismay. But turnabout is fair play, which is why Captain Aresh makes his own declaration on their way back…