HELPP

it's a manhwa where the mc is a girl with long black hair, she gets bullied by her classmates and there's a scene where she get pushed into a wardrobe plastered all over with those papers to ward off demons. iirc she met a vampire after that, and there's a red line/rope connecting her with that vampire guy whenever she gets injured/her blood come out. it's a pretty popular manhwa back then. if it helps there's a specific scene where the mc got her period and the red line appears and the vampire tried to see her in the bathroom