@Istvan90623 There are a few people in the story which are Lady Rose's potential love interests in the game, and are involved with this version's Fii somehow. It gets confusing because so many of them get thrown at us one after another.
There's Prince Seth, Fii's ex-fiance and the heir to the throne. She didn't like him because he reminds her of her original self's brother, who is the source of her trauma. We haven't really seen him, but it's hinted that he probably actually likes Fii a lot more than he lets on (so I still don't know why he annulled the engagement).
There's Nika-sama, Prince Seth's big brother who, as the son of a mistress, is not the royal heir. Nika has always been very kind to Fii, his little brother's fiance, acting -- as the world saw it -- as a gentle older brother to Fii herself. It's very, very strongly hinted that he loves her, but kept his feelings to himself. As of chapter 10, Fii just said she never thought of him as a brother (because to her, brother = trauma, and Nika was always gentle and sweet), which, combined with the fact that she's no longer Seth's fiance, means that he can finally be true to his feelings. When he said in this chapter that he will try to obtain what he desires, Fii misunderstood him to mean he's aiming for the throne. Nope. He wants her.
The King doesn't count, though he clearly is very fond of Fii, thinking of her as a daughter. As of Chapter 10, it was implied that he gave Nika permission to pursue her with his "You would be okay, too [to make Fii happy?]" comment.
There's Evan Douglas, throwaway "puppy dog" character from chapter 2. Fell in love with her, offered to run away with her when she got kicked out. Pointless.
There's her stepbrother, Jed Suwarose, a devious yandere type. Originally possessed conflicted feelings towards Fii (both admiration and jealousy, and perhaps a sense of annoyance at her insistence to keep her distance). As of chapter 3, certified sister complex after he saw the new side of his big sis completely different from the perfect and distant Lady Rose he knew.
There's Nancy, aka Nana-chan, the innocent nun who is the oasis of Fii's weary heart. Lilies and love.
There's Merwin Cravit, aka Mel-chan, the genius former classmate of Fii's, who's taken an interest in her peculiar actions and serves as her interrogation partner (lol) in chapters 7-8.
TL;DR just ship Nika-sama like the rest of us.