Manga artist Rohan Kishibe possesses a supernatural ability called Heaven's Door, which allows him to turn people into living books, reading their memories and even writing commands that they must obey. While seeking inspiration for his work, Rohan is drawn back to a haunting memory from his youth. Years ago, while staying at his grandmothers inn, a dejected teenage Rohan met a mysterious and beautiful woman named Nanase. During a late-night conversation, she told him a chilling rumor about the worlds darkest and most evil painting, a cursed work created two hundred fifty years ago by an obscure artist named Nizaemon Yamamura using an impossibly black pigment from a sacred tree. She warned him never to seek it out, claiming it was hidden deep within the Louvre Museum in Paris.

In the present day, now a famous and successful manga artist, Rohan sees a reproduction of a pitch-black painting in an auction catalogue and his memories of Nanase resurface. Determined to use the real thing as research, he outbids competitors to acquire the painting, titled Noire by an artist named Maurice Legrand. However, when the painting arrives, he finds the black pigment disappointingly ordinary. A mysterious French phrase written on the back of the canvas, This is the black seen at the Louvre. remorse, suggests the true darkness lies elsewhere.

Accompanied by his cheerful and long-suffering editor, Kyoka Izumi, Rohan travels to Paris and demands to see the legendary Black Painting. Despite museum records showing no such work exists, his persistence leads him and Izumi, along with an art appraiser and a museum guide, to a forgotten underground storage vault labeled Warehouse Z-13. There, they discover the terrifying truth behind the paintings curse. The artifact does not just depict darkness; it actively absorbs the memories and sorrows of anyone who views it, trapping them in an endless nightmare. As the group is picked off one by one by phantoms conjured from their own pasts, Rohan confronts the painting and finally learns the tragic secret of the woman Nanase, whose connection to the artwork is far deeper than he ever imagined.