Harajuku Lovers Bumblebee Hoodie Vest

Excellent condition, only worn once There is a small stain on the back of one of the sleeves (see photo) I’m confused about sizing. The tag says “12”, but it looks much too long to be a girl’s/children’s size. It is pretty tiny, so I’m listing it as a women’s XS. It was a gift so I’m not sure what department it came from. I took measurements just so you can be sure. Pit to pit is 16” with no stretch Length is 21” Please see my “Welcome to My Closet” listing for seller info prior to purchasing!