Headhunted to Another World: From Salaryman to Big Four! Vol. 4

PROMOTION WITH A PRICE?!
Salaryman-turned-heavenly king Uchimura leads the Demon Army against a horde of invading wyverns. The army struggles valiantly but is overwhelmed by the appearance of a titanic dragon—that is, until the Demon Overlord arrives. After dealing with this threat, the Demon Overlord makes the following unexpected announcement: “You, Uchimura, shall become the next king of the Demon Army!!” While striving to deal with this unexpected promotion, Uchimura heads to his next mission, where he faces a new, severe problem.
Series Overview: Uchimura Dennosuke is just an ordinary Japanese salaryman, until he’s sent to work in Vietnam where he dies in a hit-and-run accident. Uchimura is reincarnated and summoned to another world by the Demon King, who offers him a new job–as one of the Four Heavenly Kings of his army! Uchimura is faced with an offer he can’t refuse, but can he do the job?