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.
A trading company employee's girlfriend loses her memory while on a trip. In place of the friend who was supposed to have accompanied her the whole time is a mysterious man.
Newspaper reporter Kenzo let a strange woman Emi took taxi while on the way home from a business trip. Later, when he stopped by his girlfriend Nobuko's house to give her souvenir, he noticed that the suitcase had been replaced by Emi's. A knife with blood wiped out came out of Emi's trunk. Nobuko's older brother Kyosuke is a university professor, but he is also a famous detective. The next day, Kyosuke made Kenzo follow Emi's elder sister, Yuri, who came to exchange the trunk. Emi and Yuri are daughters of the landowner Kayama family, but they were both children of their ex-wife. His second wife, Shizue, has Miyako, another kid. Emi had a bad time with Shizue and left home, and she had just returned for the first time in three years...
Kenji, a disciple of the famous detective Kyosuke Kozu, had a strange experience in the world. He was asked by a woman named Shoko Ima to find the corpse in the soil. Shoko is a famous dancer in the modern ballet world, and she just married doctor Fujimoto 10 days ago. However, on that day, Shoko had disappeared. Her corpse seems to be at the base of the ginkgo tree in the house of the sculptor Kagawa, who was rumored to have a romantic relationship. Police arrested Konosuke. However, Kagawa was also suspicious.
