Isekai Office Worker follows 29-year-old Seiichirou Kondou, a man so overworked that he has long accepted the life of a corporate slave as normal. His routine shatters when he sees the ground split open and swallow a woman, and his attempt to save her sends both of them into another world. There, he learns that the kingdom has summoned a saint to protect it from a plague, and that he has been dragged into the crisis as an unexpected bystander.
The kingdom tries to make up for the trouble by promising Kondou a comfortable life and the fulfillment of any wish he might have. To everyone’s surprise, he asks for a job instead. Kondou then becomes an accountant at the Royal Palace, where he throws himself into his work with the same precision and endurance that defined his life back home. His careful, accurate accounting soon draws the attention of high-ranking officials and knights alike, especially Aresh Indolark, the cold-hearted Knight Captain.
As Kondou settles into this new and exhausting world, he faces a dangerous environment that is no less demanding than the one he left behind. Yet even amid pressure and uncertainty, he begins to find comfort in Aresh’s company, and the knight’s icy demeanor may hide more than it first appears.