she's traumatized dude, in the school incident less than 20 students survived. it's implying that because she's already lost a ton of friends, she doesn't want to lose her brother as well.
Just like whatintheBL said she's not ignorant but rather afraid to lose someone important again after experiencing such horrible thing. I think in the emotional state that she is now, I might also say the same thing as her after all she only have 2 family member left.
Every time I come back to this manhwa bad things happen and I leave it and again come back and again and again
leave and not come back
Lmao no