Salaryman ga Isekai ni Ittara Shitennou ni Natta Hanashi

Dennosuke Uchimura spent years as an ordinary salaryman, sent to countries and assignments nobody else wanted without magic, superhuman strength, or much recognition for his effort. Then he receives the strangest promotion imaginable: the Demon Lord summons him to another world and offers him the vacant seat among his four top generals.

Uchimura gains no legendary power to compensate for being human, so he relies on the only abilities he truly mastered: solving problems, negotiating, reading people, and turning crises into agreements everyone can live with. Between tribes unwilling to cooperate and growing dissent inside the demon army, he discovers that years of brutal corporate work may have been perfect training for an executive position where a failed meeting can literally get him killed.