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 language, ACTION series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc 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.