Isekai Office Worker: The Other World's Books Depend on the Bean Counter.

Seiichirou Kondou gets caught up in a summoning ritual and is transported to a parallel world called Romany Kingdom. Having worked day and night, he demands a job and joins the Royal Accounting Department. After narrowly surviving a tonic’s deadly side effects with the aid of magic, Seiichirou entrusts himself to Aresh, captain of the Third Royal Order, known as the Ice Prince.