Boku no Mii-chan

"Anyone will do. Let's get married." Morio, a wealthy scion, has been a recluse for 10 years. For the sake of his bedridden grandmother, he arranges a marriage interview, but the person who shows up is a tall, beautiful foreigner... a man!? Morio is surprised, but the man, Mitya, gently heals Morio's heart, and Morio proposes to him♥ Mitya formally agrees to move in with Morio, but in fact, Mitya suffered a deep emotional scar in in the past in his homeland!?

(Source: Tokuma Shoten, translated)