Wandering Detective: Tragedy in Red Valley  Mr. Nagumo, a wealthy landowner, reportedly died in a plane crash in Aikadawa Valley, but his sister Misako Kayama knows that he was a good pilot and suspects that there was foul play. The unscrupulous land developer Kido attempts to use documents bearing Mr. Nagumo's signature to take over the land he owned in the valley and create golf courses there. When the farmer living there, Mr. Ueda, refuses to agree to the takeover, Kido sets an exorbitant monthly rent of 600,000 yen to squeeze him out. Under the guise of running a tourism company, Kido uses his enforcers, including Southpaw Gen and Tetsu the Spade, to take out anyone in his way. A young drifter named Goro Saionji, a private detective hired by Shinnippon Kaihatsu to investigate Mr. Nagumo's death, stumbles upon the conflict when he sees Mr. Ueda's daughter Chikako being attacked and saves her. He chooses to help the farmer's family and solve the mystery of Mr. Nagumo's death. Kido's men poison the farm's water supply, killing their cows. Mr. Ueda confronts them but is beaten and told to leave the farm. Goro sneaks into Kido's palce and confronts his girlfriend with a bottle of her German nail polish that he found at Mr. Nagumo's crash site. At the crash site he shows her the parachute that he found one kilometer away and surmises that she used her experience as a former flight attendant to disable the plane and parachute out of it before the crash. She agrees to confess but is shot dead by Kido's men. Kido's men then set fire to the stables on Mr. Ueda's farm and kidnap Misako, taking her to Kido's place. Kido attempts to rape her but is stopped by Goro. Goro shows Kido a newspaper article about a missing hiker and surmises that Mr. Naguto was still alive after the crash and was forced to sign the papers before Kido's men murdered him and placed the missing hiker's disfigured and unidentifiable body in the plane. Kido insists that Goro has no evidence, but Goro produces Mr. Naguto's body, which he found after an avalanche, and says that the bullet used to kill Naguto matches the one used to kill Kido's girlfriend, both of which came from Kido's gun.