Right now the only redeeming quality of her is her character design... like SHE'S SO FUCKING BEAUTIFUL (I MEAN EVERYBODY IS IN THIS MANGA) BUT SHE HAS TO BE MY TOP 1 FAVORITE CHARACTER BASED ON THE DESIGN ALONE... YES I DO LOVE ME SOME DARK HAIRED GIRLS WITH DARK LIPSTICK
maybe because their father were absent and she had only her older brother and now she is scared of losing him (Got this from the brother phrase "He is not only our Na-kun anymore" or something like this lmao). At least this is what I understood
I hope Sera actually has a sound reason of being mad that her brother has a girlfriend and not the"I love my brother" or "somewhat" incest trope