...We might want to later.

[Sometime when it isn't pouring down rain and also nearly lockdown.

He shrinks a little into his own raincoat, scanning their surroundings.]

This is already a contained world. I think... it's also probably possible to create a barrier only certain people can cross. [That's the trick Morimori used, to keep humans out of their part of the forest.] Anyone else just gets diverted and lost.