Ouji-sama no Hanryo wa Batsuichi Arafou

Overview

Tatsumi Yagasaki, a workaholic writer worn down by life, is forced to assist prince Nico of the Kingdom of Rashid, who came to Japan to write a guidebook about the country. Tatsumi is exhausted from being at the mercy of the prince all day long, but he's swayed by Nico's honest and naive smile. Before he realizes it, he gets drunk and sleeps with him. While Nico is somehow both happy and embarrassed, Tatsumi is terrified that he might be in for severe punishment! An old custom dictates that Nico must spend the rest of his life with the one who takes his virtue, so Tatsumi is set to be his spouse! This is a love story between a divorced man nearing his forties and a prince that transcends status and country! (Source: Renta!) Note: Includes one extra chapter.

Source: AniList