The Scar that Invokes the Past After going over the characteristics of the boy, Conan realizes who it is. During the midnight snack, Conan uses Mouri to solve the case. Conan reveals the boy who was honest would never have taken the money. He reveals the identity of the boy to be the butler, Taisuke Houya; The boy's nickname was revealed to be "gari" because he liked to eat Gari. Later, Kiyonaga barges in and accuses one of the men with the scar as a serial killer from a past case. The man reveals that he copied the scar from a strange man a few years ago whom they realize is the serial killer. The next day, a criminal psychologist named Douji Hiramune challenges the serial killer to reveal himself. He happens to live in the same apartment complex as Ayumi where the Detective Boys are staying with. Ai later reveals to Conan she saw a mysterious man whistling "Let It Be" which is the serial killer's trademark.