Are you referring to the black thing sticking out from under the coat?
I could see that having a low v-neck and having straps that fasten across the back of her neck or criss-crossing behind her shoulders.
Or it could be kinda like a girdle, or an overskirt piece with a high waist.
FF9 cosplay? Hit me up!
I now have a Tumblr
. Sometimes I use it.