Kaiju Gomera VS Kamen Yaiba (Prologue) Conan and his friends are invited to the production presentation of the new office building completion commemorative movie "Big Monster Gomera vs Kamen Yaiba" and come to Nissho TV in Osaka. During the production announcement, an accident occurred in which a talented producer Yonekura was killed by being laid under a huge monster figure in a warehouse. The rope that supported the figure was cut with a knife, and Inspector Otaki of the Osaka Prefectural Police proceeded with the investigation as an incident, not as an accident. The suspects are narrowed down to three producers, Kosugi, Mihara, and Takauchi, who are subordinates of Yonekura.