the reason can be du to the modus operandi of that ghost, the main attack of that particular ghost is not cursing to provoke sickness to his victims, but "bad luck that provoke death", each time he appear in the serie, miko is prone to having an fatal accident, remember chapter 43 when she was saved by michiru before being isekaied into an other world by truck kun, or in chapter 64 with a vase falling, potentially, the death of miko's father can potentially traced to him.
the cursing seem to be a defensive mode when someone try to discover the ghost, or because someone is perceived as an obstacle between the ghost and his prey like here with michiru, it's the second time she save miko.
the ghost seem to be a shinigami, with the costume and accessory that resemble a japanese farmer rice cultivator:
https://www.dreamstime.com/royalty-...ice-farmers-planting-rice-paddy-image12914305
the asian version of our old westerner grim reaper, and i higly doubt that his face is his real face, but a mask made from real skin a la leather face.
another thing i found, is that the ghost approach miko little by little, if we consider that the ghost was here since she was in elementary school like in the photo of chapter 50, the more he is near her, the more violent and recurent his attack will be.
all of that lead me to 2 possible explaination of how miko is able to see dead spirit :
first one, the least possible for me, she was cursed by the shinigami to see the dead spirit, and when you see the kind of horror she see, it lead to madness or jumping into the sea with concrete shoes.
the second one, she has faced death with the accident of her father, and because of it she is able to see dead spirit, think of it like harry potter and sombral for the concrete exemple.
and because she is friend with hanna, who is literrally a living battery that can buff anything, miko's power to see thing upgrade really fast, like mitsue the old medium, just being near hanna level up the capacity of the old medium as explain in chapter 27
