A filmmaker named Goro Hanawa commits suicide. Goro had appeared happy before his suicide. His best friend, a novelist named Kogito Choko, discovers the suicide via an audiotape recorded by Goro; he had sent forty tapes to Kogito. Chikashi Choko, Goro's sister and Kogito's wife, also learns that Goro died. To learn why Goro had killed himself, Kogito listens to the tapes.