Kyosuke (Masaomi Kondo) and his sister Nobuko (Yoko Moriguchi) were invited to the 10th anniversary party of the travel agency "Pigeon". At that seat, Ayako, the younger sister of President Gentaro, is shot dead. Other venues included Gentaro's brother-in-law, Palau branch manager Kiriyama, secretary manager Anna, and Miyo, who runs a restaurant on Palau Island. A few days later, Nobuko goes on a trip to Palau. She is kidnapped by someone in the field, and Kyosuke and other related parties rush to her. In Palau, there was Toshinosuke, the founder of Pigeon and retired. He was once a detective called "Sakuradamon Demon", but was accused of being arrested 15 years ago and was ousted from the Metropolitan Police Department. It was Kyosuke who proved his innocence.

Detective Kyosuke Kozu's Murder Reasoning 10

Shunsuke Honma is a detective from the #1 investigation team at the Tokyo Metropolitan Police Department. Shunsuke takes a leave from work due to an injury. One day, his relative comes to see him and asks him if he can find his missing fiance Akiko Sekine. Shunsuke takes on the job and enlists the help of Detective Sadao Ikari. The detectives soon uncover the shocking truth behind the missing woman.