The girl (Iris) is not allowed to leave the room, and she spends her days waiting for the young man (Ruki) to return and getting bread and being embraced.
He is now unstable and violent, but he was a very kind boy when he lived like a family in an orphanage.
Iris can't go out hoping for the day when he will return to her because she has no memory of "that day".
She remembers her missing memory when she stopped being obedient ...