The second part of Genjitsu Shugi Yuusha no Oukoku Saikenki.

Summoned to a fantasy world, Kazuya Souma is ruling a kingdom with a nontraditional (and very human) route of administrative reform. He’s tackling food shortages, mastering dark magic, and dazzling a few ladies along the way. Despite his latest good intentions, Kazuya breaks the ban on war to defeat a military dictatorship. Now, he must answer to the Gran Chaos Empire’s idealistic leader…uh oh.