Detective Kyosuke Kozu's Murder Reasoning II (1985)

Reportage writer Kenzo has made an interview appointment with Morishima, the mastermind behind the political and business world. On that day, Morishima is killed and a 200 million yen diamond is stolen. The diamond was brought by jeweler Kuhara to sell to Morishima. A woman named Maki who was present and disappeared immediately after the incident is suspicious. However, the site is a completely closed room. Kenzo's older brother, Matsushita, the chief of the investigation section, also shook his head...