While Kogoro is investigating the false kidnapping of the Red Sheep game meant to test a boyfriend's courage and love, Conan and Ran run into someone wearing a red sheep costume in the street at night. After the red sheep departs, they find the body of restaurant La Mucho owner and head cook Wakabayashi Tetsusaburo. Because the restaurant is also the workplace of Takigawa Ami, who set up the false kidnapping, and her boyfriend Beppu Ryota, they believe the incidents are related and visit the restaurant. While asking about alibis, they learn that since several weeks ago, videos featuring a red sheep pranking couples and running away have been getting a lot of attention on a video sharing site. Meanwhile, the police searching Wakabayashi's home discover a threatening message on his computer...
