How a Realist Hero Rebuilt the Kingdom: Omnibus Vol. 1 (manga)

Contains the full Volume 1 and 2! "O, Hero!"
With that cliched line, Kazuya Souma finds himself summoned to another world and his adventure in administration begins! Upon presenting a plan to strengthen his new land economically and militarily, the king cedes the throne to him and Souma finds himself stuck with the top job! What's more, he's betrothed to the outgoing king's daughter?! In order to get the country back on its feet, Souma must summon the wise, the talented, and the gifted to his side. And even when he does manage to catch a break, a day off with his staff provides anything but: rebelling retainers, natural disasters, and the threat of war all await. Can Souma keep up without succumbing to the stress?