The film takes place in an asylum, in the countryside. Amid a torrential rainstorm, a janitor wanders through the halls revealing the various patients suffering from mental illness. The next day, a young woman arrives and is surprised to see her father, the janitor, working there. Her mother is an inmate in the asylum and had gone insane due to the cruelty of her husband, the janitor, when he was a sailor. The husband, feeling guilty, had taken a job at the asylum to care for her. The daughter announces that she is soon to marry a fine young man, but the janitor begins to worry, since society at the time still maintained the prejudiced view that mental illness was inherited. If the young man's family learns about the mother, the marriage might be called off. At work, the janitor's relationship with his wife, unknown to the asylum, interferes with his job, as he gets into a fight with some male inmates when his wife is hit, and he is sternly scolded by the head doctor. All this sparks in the janitor to experience a number of fantasies, as he slowly loses control of his border between dreams and reality. He first has a daydream about winning a chest of drawers at a lottery that he could give to his daughter as part of her dowry. When his daughter comes to tell him her marriage is in trouble, he thinks about taking his wife away from the asylum to hide her existence. Finally, he fantasizes about killing the head doctor, but that reverie goes out of hand as a bearded inmate is seen marrying his daughter. The janitor finally dreams of distributing masks to the inmates, providing them at last with happy faces. He returns to work mopping the floors, no longer able to visit his wife's ward because he had lost the keys. He sees the bearded inmate pass by, who bows to him for the first time, as if bowing to his father-in-law.
A Page of Madness was first screened in Tokyo on July 10, 1926. Screenings would have included live narration by a storyteller or benshi as well as musical accompaniment. The famous benshi Musei Tokugawa narrated the film at the Musashinokan theater in Shinjuku in Tokyo.
Reception of the film since its rediscovery has been mostly positive. Dennis Schwartz from Ozus' World Movie Reviews awarded the film a grade A, calling it "a vibrant and unsettling work of great emotional power". Time Out Magazine, praised the film, writing, "A Page of Madness remains one of the most radical and challenging Japanese movies ever seen here." Panos Kotzathanasis from Asian Movie Pulse.com called it "a masterpiece", praising the film's acting, music, and imagery. Jonathan Crow from Allmovie praised its "eerie, painted sets", lighting, and editing, calling it "a striking exploration of the nature of madness". Nottingham Culture's BBC preview of the film called it, "a balletic musing on our subconscious nightmares, examining dream states in a way that is both beautiful and highly disturbing." Jonathan Rosenbaum of The Chicago Reader praised the film's expressionist style, imagery, and depictions of madness as being "both startling and mesmerizing". It was later included at number 50 in Slant Magazines "100 Best Horror Movies of All Time", citing the film's visuals and atmosphere as 'lingering long after the film ends'.
