Myserious guest summoned by Theodore’s experimental magic circle.
Wears a snowy white mask that shows no emotion. Seems to know everything about the treehouse and the world surrounding it. She is also the calmest one among the three summoned guests.
Not exactly friendly to Alice. She uses all kinds of methods to prevent Alice from returning to the world beyond the skylight. However, for some unknown reason, the Masked Girl always behaves herself whenever Deemo is around.

The Masked Girl carries a pocket watch with her all the time. A concealed message is carved on the inside of the pocket watch: “yrasrevinna ht5”.