Kyotaro Nishimura Travel Mystery 72.

University professor Kenzo Oshima (Hisamatsu Nobumi) is stabbed to death by someone in an alleyway in Tokyo, and Inspector Totsukawa (Takahashi Hideki) and Detective Kamei (Takada Junji) of the Metropolitan Police Department's Investigation Department's Investigative Division 1 arrive on the scene. According to the first finder, the victim died after saying "Totsukawa...". Oshima was famous as the leading authority on mitochondria, but he had never met Totsukawa... Totsukawa is puzzled, but begins to investigate, and discovers that a suspicious man has been caught on a security camera near the crime scene. Seeking a clue, Totsukawa and his colleagues interview associate professor Hayase Yumi (Kurotani Yuka) and the president of a biotechnology company, Koji Nakazono (Nakamura Shunsuke), who was assisting them in their research, to find out what happened. They find out that the man caught on the security camera is none other than their childhood friend, Akaike Shogoro (Matsuo Satoshi).