Seiichirou Kondou, a salaryman approaching his 30s, gets caught up in a holy maiden summoning ritual and is transported to a parallel world called Romany Kingdom. Having worked day and night, he developed the mindset of a corporate slave and even demanded work in this new world, which landed him an accounting job at the Royal Accounting Department.
 
During his hectic days rebuilding the accounting department, Seiichirou came across a nutritional tonic that wiped away any fatigue. Thanks to the tonic, Seiichirou's chronic ailments and exhaustion completely disappeared, leaving him overjoyed. But because he had no resistance to the world's magic, the side effects put his life in danger!
 
The only way to survive was to have someone with magic help accustom his body to magical energy, so with no other choice Seiichirou entrusts himself to Aresh, captain of the Third Royal Order, known as the Ice Prince.
 
(Source: Crunchyroll)

[Wiki (jp)](https://ja.wikipedia.org/wiki/鈴木琢磨)

Once upon a time, in the not too distant past, a holy maiden was summoned. Not just any holy maiden—one hailing from modern Japan. But this story is not her story. This is the tale of the humble accountant, Kondou, who accompanied her and his trials and woes as he accounts in a new world... But no tale is complete without a love interest. And who better to play that role than the handsome knight captain Aresh? Will he begin a personal quest to save said bean counter—who toils around the clock—or is Kondou doomed to be married to his work evermore...?! 
 
(Source: Yen Press)

Seiichirou Kondou is a 29-year-old accountant and major workaholic. When he's accidentally transported to another world, not only does he demand a job, he starts whipping the lackadaisical Royal Accounting Department into shape! But when he gets in over his head and nearly dies from overwork, the handsome Commander Aresh steps in to save him, and the two develop a unique, physical relationship...as a form of medical treatment?!
 
(Source: Yen Press)

Helmut Somaria