Yeah, I'm developing a potential anime right now and I'm desperately trying to create another main character and potential love interest for the main protagonist. I've got absolutely no idea where to go with her, so I was hoping you guys might be able to help out
I'm looking for a character to help balance out the different physical and personality attributes found within the main group, so I should probably let you guys in on who they are first:

(p.s. - I plan on putting a five-year time-skip into this story, so no, I'm not making a 13 year-old and 12 year-old fall in lovexd)
I'm looking for a character to help balance out the different physical and personality attributes found within the main group, so I should probably let you guys in on who they are first:
- 13 year-old boy whose slightly arrogant and not the friendliest of sorts, but also intelligent, cunning, and helpful to those who need it. He's not very skilled in close combat at first, his only real skills being his speed and some prowess with throwing stars, and he usually relies on a special hidden power of his to get him and his group out of tight spots.
- 17 year-old girl whose somewhat stubborn and aggressive, but also wise and secretly caring. She's pretty skilled in hand-to-hand combat, even against multiple enemies, but not so much with weapons.
- 18 year-old man whose street-smart and has a typically clueless and curious persona, but he's also quite insightful and can be very serious when necessary, willing to do anything to protect those he cares about. He's not very skilled in close combat, but he's an excellent marksman with his two firearms.
- 22 year-old twins with very friendly, but also serious personas. They almost always say the same thing at the same time, much to the curiosity and frustration of the other members of the group, but in truth, they do have their own thoughts and opinions, and are just very good at understanding what the other is feeling at any given time. Both are highly capable in hand-to-hand combat and have prowess with shuriken and their katanas.
(p.s. - I plan on putting a five-year time-skip into this story, so no, I'm not making a 13 year-old and 12 year-old fall in lovexd)