As a Japanese art student working in an antique shop, Eiri Kurahashi undergoes a mysterious transformation that perplexes his friends. They attribute his odd behavior to a girl, and they might be onto something. Eiri becomes fixated on a doll-like girl trapped inside a Venetian glass acquired by his uncle. Despite being in a world confined within the glass, the girl, named Cossette d’Auvergne, captivates Eiri's every thought. His sketchbook fills with her image, and his infatuation grows. Discovering her tragic past through a portrait by the enigmatic artist Marchello Orlando, Eiri learns of Cossette's brutal demise. One fateful night, as he shuts the shop, a voice pleads for him to stay. This leads Eiri to strike a mysterious deal with his haunting obsession, delving into unknown territories.