According to the subtitles on my Criterion blu-ray of this thing, at the end when her head's looking at the crazy piano/body shenanigans and smiling she says, "That's naughty."
First movie I ever felt compelled to get the blu-ray of. You know, because you haven't lived until you see a girl's disembodied head biting another girl in the ass unconvincingly bluescreened over a sunset matte painting in glorious hi-def.
I should say "wonderfully unconvincingly" because it all just adds to how beautifully fevered and surreal this whole thing is.
If you haven't seen this movie and you are on the fence because you have been let down before by movies (especially Japanese movies) that look wacky and fun in the trailers but turn out to be boring and detached and filled with nothing ... go watch this because it is genuinely great on multiple levels and will not let you down.