Who would be usuras bffs or potential love interests 😏
You mean Urusa? XD
Well, it depends on the version! So far I have two: one where she ends up in General Studies and another where she studies in the Hero Course.
In the General Studies version, she's Hitoshi Shinsou's best friend. Since in this version she's the class representative for class 1C (I think General Studies was 1C and 1D), she approaches him after noticing how distant he is and eventually discovers that he wants to enter the Hero Course. Although Urusa isn't particularly interested in being a hero in this universe, she decides to help him train for the sports festival. In fact, they team up so he can advance to the final round without any problems. Essentially, Urusa acts as his bodyguard throughout the festival until the individual matches, where Hitoshi ends up losing to Izuku, just like in canon. Urusa, in an attempt to at least achieve something for him, continues on to the finals and even wins the sports festival because she shows no mercy to Bakugou, and Todoroki would continue using his ice technique.
Urusa wins the festival, but refuses the prize because it's non-transferable and she can't give it to Hitoshi, which leaves a considerable impression on the rest of the world. However, she stays by Hitoshi's side throughout, so yes, they get along very well. As for romantic interest, it's not something that has been explored here yet, given that in this universe Urusa doesn't interact much with the Hero Course.
Now, in the version where she's in the Hero Course, things change: she gets along with practically everyone, but Momo Yaoyorozu and Fumikage Tokoyami stand out as her "best friends."
(Or rather, fellow sufferers due to something that will happen in the story, though I'm still not sure if it will be a definitive part of the plot.)
Mainly Yaoyorozu, since Urusa is very skilled with her hands and is very good at cooking, sewing, and wood carving, and I think Yaoyorozu would greatly admire that kind of versatility. Urusa is also close to Tsuyu Asui because they are both mutants (I plan to add bear-like features to Urusa's design, if I can manage it, but I'll see) and have long hair. Urusa would style Momo and Tsuyu's hair a lot.
As for love interests in this universe… well, there are three options, but they aren't very developed. And it's more likely that she's the love interest of someone than the one being interested. The first time I was building Urusa's story with the AI, I got Bakugou and Kirishima. Bakugou made me raise an eyebrow, especially since the next two times I opened a chat with Urusa, he ended up in a rivalry with her. The second time, I got Midoriya and Kirishima. With Midoriya, because Urusa saw him breaking his fingers on the first day and said, "Damn it. This guy isn't going to die while I'm around," so she makes sure to train him too.
As for Kirishima, being, so to speak, "the universal constant," I'm particularly drawn to him as the ultimate love interest. In the three chats I've done with Urusa, he admires her a lot and loves that she's so strong. He also finds her very pretty and really enjoys sparring with her because Urusa is tough in a fight, and Urusa likes Kirishima because she can beat him up without actually hurting him. They both benefit a lot from each other in training, so I think it would be funny if he were her "ultimate partner."
Seeing Urusa with Midoriya is also funny, since Urusa is rugged and wild while Midoriya is that shy nerd who's fascinated by Urusa's nature. They'd basically be the "Excuse me, he ordered without pickles" meme. XD
Thanks for asking!