Not good. not bad. The FMC isn't charismatic enough for me to carry the story so far, and I kept looking for some deeper reason for the MC's actions but not liking school and can't sleep are the only two I see provided -- which are relatable but neither interesting nor necessarily tear-jerking for me.
Hope the next chapters add some sort of conflict/development.
So I asked myself what the dumbest possible ending to this story would be and my gut tells me vampire-oneechan is gonna fall hard for MC and inexplicably turn human after a last-second reveal this vampire thing works both ways. Calling it now.
I knew he's gonna call her by "-chan", because that's something any sensible person (me) would do.
Though he needs to wait for couple years to properly look down on her.