The Other World's Books Depend on the Bean Counter, Vol. 3 (light novel)
Magic Research Exchange Plan

Cold feet or passion running hot?Seiichirou, a typical corporate slave, was mistakenly summoned to another world alongside Yua Shiraishi, the Holy Maiden. There, he and the handsome young knight, Aresh, began a physical relationship out of necessity. Now they’ve become true lovers. Unsure how to face Aresh’s deepening feelings, Seiichirou throws himself into work. Conveniently, he’s appointed to guide a foreign delegation led by a prince. But the outfit Aresh picks for Seiichirou to wear to the royal welcome party sparks a huge argument. As days pass without reconciliation, Aresh is approached with marriage talks! When the spell to send Seiichirou and Yua back to Japan is completed, what will the two of them choose to do?