Masanao Ushio and other detectives from Shinjuku West PD discover the strangled dead body of a woman in an empty building in West Shinjuku in Tokyo. According to her husband Takeshi, the murdered Chieko Akiba was a top salesperson at the insurance company where she worked, but quit her job three months ago and planned to open a beauty salon after buying the building which happens to be the crime scene. The call history on her mobile phone reveals the victim answered a call at 8:16 PM and is presumed to have been murdered immediately afterwards. However, Ushio is surprised to hear who was on the other side of the call: Kyoko Yamano, a woman who accompanied Ushio under an umbrella on a rainy night one year ago and whose husband was killed by someone that very night...