It's a world that exists outside of the dimensional barrier.

Dimensional barrier?

For instance, at a theater, there's a space between the audience and the stage.

World ②

World ①

Dimensional Barrier

There's a barrier that's invisible to the naked eye, and yet isn't easily broken, isn't there?

A kind of invisible, intangible, insurmountable barrier between two worlds that can't interact.

So after the divide between the two worlds was breached, they sealed it off with a double-sided barrier, I see!

A world that's kept so secret...

I wonder what kind of place it is.