"Le Portrait de Petite Cossette" is a three-episode anime OVA that blends psychological horror, romance, and supernatural elements. The narrative centers on Eiri Kurahashi, a young art student working in his uncle’s antique shop. While examining a Venetian glass, he becomes entranced by the image of a girl named Cossette d’Auvergne, who lived centuries ago. Cossette reveals herself to Eiri, explaining that she was murdered by her lover, Marcello Orlando, a painter who trapped her soul within the glass. She claims that Eiri is Marcello’s reincarnation and demands that he atone for Marcello’s sins by enduring the suffering she experienced.

As Eiri becomes increasingly obsessed with Cossette, his reality begins to unravel. He experiences vivid hallucinations, physical pain, and emotional torment, all while Cossette manipulates him into reliving her tragic past. Eiri’s relationships with those around him, including his childhood friend Shouko, deteriorate as he isolates himself in his fixation on Cossette. The story delves into themes of guilt, redemption, and the destructive nature of obsession, as Eiri struggles to discern whether Cossette is a vengeful spirit or a manifestation of his own psyche.

The anime’s visual and auditory elements enhance its eerie atmosphere, with surreal imagery and haunting music underscoring the psychological tension. The characters are intricately tied to the central mystery: Eiri’s descent into madness, Cossette’s tragic backstory, and Marcello’s role in perpetuating the cycle of suffering. The narrative culminates in a confrontation where Eiri must confront the truth about his connection to Cossette and decide whether to break free from her grasp or succumb to her demands for retribution. The series leaves much of its resolution open to interpretation, emphasizing the ambiguity of its supernatural and psychological elements.