It's that youkai's fault.

There is an easy way of getting out of here.

Dying.

But committing suicide is no good. If you use such methods, your brain will think you actually died and kill your real body.

This will happen unless you're destroyed by a supernatural force beyond your understanding.

So in short, meeting your own doppelgänger is a valid way out of here.

It looks like you're my otherwordly isotope or a resident of another world so the conditions would be met.

But it seems we had our [Boundary of recognition] altered by that youkai.

We can only think of each other as strangers that look similiar so the condition is not met.

Then that means earlier Mary has only disappeared from here...