The "deep" version of the story should end with a pyrrhic victory. To escape, one of the sisters must sacrifice their reputation or stay behind to ensure the others get out. This forces the characters to choose between their personal survival and their loyalty to each other, emphasizing the psychological scars left by the institution.
Japanese media :
The narrative structure focuses heavily on the buildup, making the eventual "climax" of the plot feel earned within the context of the story. Sei Dorei Gakuen 2
It successfully creates a feeling of isolation within the school walls. The "deep" version of the story should end