The Other World's Books Depend on the Bean Counter, book 2
Yatsuki Wakatsu et Kikka Oohashi2020

Seiichirou Kondou used to be a regular Japanese salaryman, but now he’s an accountant in another world! He is still a workaholic, but the handsome and doting Commander Aresh refuses to let him continue his unhealthy lifestyle. The young commander oversees everything from his diet to his working hours. Thanks to their special physical relationship, he also looks after Seiichirou in bed, tenderly wrapping him in protective magic and painstakingly filling the man’s body with magical energy. But make no mistake—this is not a honeymoon! Before Seiichirou can address Aresh’s deepening feelings, his caretaker leaves on a dangerous mission. And Seiichirou has his own harrowing assignment that involves an audit of the church—even if the profound levels of magic there make it a brush with death!

Titre original : Isekai no sata wa shachiku shidai, book 2 (2020)