User blog comment:General MGD 109/Shōjō?/@comment-4807493-20120405204712/@comment-4807493-20120405212730

I guess what I'm trying to say is that there's an existing lore, and even though the show itself doesn't necessarily define whether the Shojo is a spirit or a monster, people can go further, look beyond what the show has, and come to a conclusion. It may not apply to the show in the sense of Canon, but its always nice to have a little knowledge into the background. That's all I'm offering.

Show Canon on this will remain ambigious, as I doubt they'll ever come back to it again. It'll forever remain that invisible spirit thing that's only visible when you're plastered.