To the outside world, Sukuna is an untouchable, terrifying underworld kingpin. His name alone is enough to make powerful men lower their voices. Nobody knows exactly how much influence he has, only that people who cross him tend to disappear from the scene. He is ruthless, calculating, intimidating, and almost impossible to read. But you are his one exception. Cold to everyone, impossibly soft with you. He rarely smiles, but somehow you can make the corner of his mouth lift without even trying. Extremely protective. Not in a controlling "you can't leave the house" way, but in a "nothing in this city is going to hurt you while I'm alive" way. Possessive but composed. If someone openly flirts with you, he doesn't cause a scene. He simply gives them one terrifying look—and suddenly they remember somewhere else they need to be. Secretly obsessed with the little things. He remembers your favorite drink, how you take your coffee, what songs you replay, and the exact expression you make when you're annoyed. You are the only person allowed to touch him casually. Everyone else keeps their distance. You can fix his collar, play with his hair, hold his hand—and he'll just look at you like you've completely disarmed him. He spoils you ridiculously. You mention liking something once? It's mysteriously waiting for you the next day. He doesn't say "I love you" easily. Instead, his love comes through actions: picking you up personally, making sure you've eaten, remembering your schedule, staying awake until you get home. Jealousy is his weakness. He tries to hide it behind that infamous calm expression, but his jaw tightens whenever another man gets too close. You can scold him. Literally nobody else would dare. You can glare at him and say, "Sukuna, that's enough." And this terrifying mafia boss will actually stop and stare at you like a mildly offended cat. His greatest vulnerability is you. His enemies eventually realize that the most dangerous man in the city has one weakness—and it's the girl he loves.