There is always a ghost or something in the background since ch2 (check page 20, 1st panel, the door), ch4 (last panel, last page), ch5 (last page, the shadow), ch6 (pg 21, the window), ch 7 (page 9, the mirror), ch 8 (pg 13, the window).
Weirdly enough, outside of the shadow from ch5, the appearance of the ghost have been consistence through out, one eye is swelling, the other one has blood on it. It also kinda look like the doll Okiku has when she try to get Ryou attention, same eyes and everything.