The last page of Natsuki's small book is one line in Iris's handwriting.
Every version of the room is real. Nobody told you because nobody wanted to be the one who stopped it.
Below that, smaller, in someone else's hand: thank you for staying this long.
The monitor brightens. The kettle stops. The three of them look up at once, and none of them bothers to dress.
IrisYou read it, didn't you.
MayaThen it's ours now.
Maya takes the book, sets it down, then puts your hands somewhere that is not the table.
NatsukiThen close the book.
You close it. The room keeps going. This is the version where you remember.