In 2004, Mechagodzilla is undergoing repair modifications after its battle with Godzilla one year earlier. Prime Minister Hayato Igarashi accepts Lead Scientist Yoshito Chujo's choice to replace the Absolute Zero Cannon with a powerful Tri-Maser.
During a meeting of the Japan Self-Defense Forces (JSDF) for the potential return of Godzilla, Admiral Taizo Tachibana briefs cadets about Godzilla's first attack. A nuclear submarine is reported missing, which is later found to have been destroyed by Godzilla. Tachibana's daughter, Yuri Tachibana, films a docudrama with her crew for BS Digital Q at Mt. Myoko, where a mysterious earthquake randomly ensues. The odd earthquake returns later that night burying a biker gang and leaving one surviving trucker who witnesses the monster, Baragon.