Kuro no Senki II: Isekai Teni shita Boku ga Saikyou nano wa Bed no Ue dake no you desu

On the day of his high school entrance exam, a boy named Crono is suddenly transported to another world.
He became the commander of the demi-human army, won many great victories, and is feted as a lord.
He gathers beautiful women one after another...
A royal-road war story with battles, domestic politics, and sex!

(Source: ComicWalker, translated)