Izumi had just lost her husband Nishimura. Nishimura had fallen down the stairs while drunk. One day, she found a tape with a woman's voice among his belongings. Izumi suspected it was evidence of an affair. A few days later, Izumi met Nishimura's friend Fujii and played the tape for him, asking if he knew who Nishimura was having an affair with. Fujii said he had no idea who the voice was, so it wasn't necessarily an affair. However, Izumi suspected that Nishimura had whistled the same tune as ...