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Kurahashi has never been the same since the hallucinations started. His condition is not medical in nature, and only seems to be triggered by an antique glass which shows him things he never would wish to see. For Kurahashi, figuring out the mystery of the Petit Cossette that appears to him in his waking dreams is a matter of life or death... and his sanity...
Kou Outori a normal high school student who experiences a repeating dream of being eaten by a beast from inside himself. When Kō meets Reiichi Kuki, the elite student who rules his school, the encounter awakens hidden powers inside him.