Hazure Skill: The Guild Member with a Worthless Skill Is Actually a Legendary Assassin, Vol. 4 (light novel) — Kennoji

A CRISIS ABROAD!
Roland and his companions are called away to the Duchy of Bardenhawk to establish a new Adventurers Guild and help the nation rebuild after its collapse during the Human-Fiend War. Unfortunately, the locals are wholly unfamiliar with the concept of quests, so the former assassin has his work cut out for him. To make matters worse, aristocrats upset with Bardenhawk's recent changes conspire to kidnap its princess, and they've hired the one person who may truly be a match for Roland...