Do you need some help putting it on? Here, this part goes on over your head like this...

[Nano holds the apron up to show her, looping it up and around Xion's neck.]

And then you just tie it closed in the back!

[Which she then circles around to help her with, tying the strings in a nice tight bow. Possibly a little tighter than she normally would, thanks to the TRIHARDO.]