Okay! This is an older movie, but i feel like I saw it around 2010 or so. It was in Japanese and a friend let me borrow it (burned dvd). It was in color and the clothing could be late 70s or early 80s— Basically, boy has a crush on a girl who becomes cursed by a spider demon? Her head detatches from the rest of her body and eight legs emerge. The likeness of every person she kills becomes burned into the back of crush boy… any ideas?

Thanks!