Kuro no Senki II: Isekai Teni Shita Boku ga Saikyou na no wa Bed no Ue dake no You desu is a Manga/Manhwa/Manhua in (English/Raw) language, ACTION series, english chapters have been translated and you can read them here. You are reading chapters on ManhwaZ fastest updating comic site. The Summary is
Kurono Crawford (Chrono Crawford), a noble of Cepheus Empire had a secret. It was that he came from a Different world… Modern Japan. Having the knowledge about the modern weapons and his sense of values, he was an existence almost like a cheat, aiming to be the “Harem king”. Abandoned by his superiors, left in command of the Empire’s rejects consisting of demi-humans such as Minotaurs, Dwarfs, and Elves, and thrust into a position as head of a poor fiefdom, Chrono will do everything he can to rebuild and strengthen his forces and revitalize the land, aided in part by his knowledge of the other world.