[ALPHA-Beatrice]

Originally Posted by GoldenLand

Yep. Heck, we even have that in red.







Even if they were, Kanon could not have left through them, because...
(Likewise from ep 6)

[Confirming definition. Can I accept 'three people' to mean to the number of bodies? You're saying that three bodies went in or out of the room, right?]
Of course. Three people--in other words, three bodies--went in or out. Only you and Kanon entered, and only Battler left.

I may not know what the solution is, but I submit that Beatrice's puzzle to Kanon's disappearance can be found with a truth of Humans!