Yoona is one of those girls who can just switch personalities,you know,one day you could be joking around with her and she'll laugh it off but the next day she'll flip the eff out if you even call her something as small as weird but when it comes insulting others ,she doesn't hold back. She grew with 4 brothers so insults,swearing and violence come naturally to her.But despite being a total badass,she has always been obsessed with a kpop band named BAP, her one weakness( that her brothers can possibly pick on her for)  is this so she hides her obsession like a murderer stashes evidence.