Sonoko brought Ran, who brought Conan, to visit the site in the country used as location in filming of a well-received romantic TV serial, where the lead actress tied a red handkerchief to a tree branch to enable her lover to find her. The success of the serial went beyond expectation and the sleep rural area became a popular spot where female visitors tied red handkerchieves all over the woods, spoiling Sonoko's scheme to lure Makoto for a romantic rendezvous. They encountered a man who claimed to be part of the TV serial crew, and commissioned by a fan to find the exact location of tree with the original red handkerchief in the show. Shortly afterwards, he was discovered, stabbed dead, at the spot.

An overly strict man is accused of murdering a woman. Is it murder or is it self-defense? Conan must investigate and figure out the truth.