Kara Kay

Kara was born on the far-off Realm Islands to a large family. She's the second-oldest, and grew up with several brothers; while her entire family has innate heat resistance, Kara's the only one out of all her siblings that has actual pyrokinesis.

She moved to the mainland for highschool, and ended up figuring out gender stuff while there. She also met Tide, who despite being far more low-key than her in personality ended up being her best friend there; anyone that bullied Tide had Kara to deal with, and Tide did her best to balance her out. She was also blissfully unaware of Tide's crush on her.

After Tide's accident, Kara moved in as her roommate and refused to leave. Tide clearly needed help, and with Tide distanced from her family and not having much of a support network to begin with she felt like it was up to her. Her refusal to back down meant Tide soon gave in and allowed her to help while she was recovering; as time passed, they started talking about what things may be like in the future, with Kara not wanting to ditch Tide after she was "better" and Tide having grown to rely on her presence and emotional support. One conversation led to Tide admitting she had feelings for her and, to her surprise, Kara reciprocating.

When Tide's childhood friend Sik showed up on their doorstep with no warning, Kara instantly wanted to take him in and make sure he was okay. Tide relented, and since then Sik has been like a little brother to the both of them. Kara helped him through his own identity nonsense, and also taught him how to fight and the basics of parkour. She doesn't regret it, even though Sik constantly gets himself into trouble. She would commit murder for him.

Misc

Kara is very physically active, and often drags the other two members of the team into it (although she's mindful about Tide's boundaries). Mostly she just tries to get Tide to do more than just get stuck being stagnant.

She's big into shounen anime and action-y stuff and the like, and has definitely tried to explain the plot of JoJo's Bizarre Adventure to Sik. Kara also plays videogames with him, although her short temper means she ragequits a lot and has to spend time screaming into a pillow before she calms down. She's actually pretty terrible at fighting games and does better with RPG or strategy games.

She's a good cook, and has fun trying new recipes. This ended up being a pretty good thing, considering Tide is often too low on spoons to do much and Sik doesn't have the attention span to cook, but she tries to get them involved if either of them are capable.

Kara sleeps on the couch a lot. Not because Tide banishes her there, but just because she likes it. Tide isn't sure how she hasn't completely destroyed her back.

She might be very distantly related to Blaze? In the sense that Blaze might be a future descendant of her family, or something. Her pyrokinesis is more along the lines of literally lighting herself on fire, though, rather than the full control Blaze has.