Minority ethnic group setting + fictional feudal clan + a world where same-sex couples can marry + the misunderstanding that they are blood-related (^^)
Cool, scheming, irresistible beauty of a bottom vs. feudal dad-type, jealous king, and paragon of virtue of a top
Older man, devoted to each other in body and soul, a pure-love story
Bottom's perspective: “You've pursued me for so long, insisting I go register our marriage, only to turn around and say...”
“I'm your older brother. You have to marry someone else.”
The bottom scoffed. “Fine. Just you wait. I'll live happily ever after with his younger brother's wife.”
Top's perspective: “I love someone.”
“The night before I was supposed to marry him, I learned a secret.”
“After that, I forced him to marry someone else.”
“Later, I knocked out the groom-to-be, became a fake groom, and climbed into his wedding bed.”
“The next day, I pretended nothing had happened.”
“I was still his good older brother.”
Theme: Hey, buddy, want to get married?