Mothra and her fairies return to Japan to warn mankind that they must return Kiryu to the sea, for the dead must not be disturbed. However Godzilla has survived to menace Japan leaving Kiryu as the nation's only defense.
| Actor | Role |
|---|---|
 Noboru KanekoYoshito Chûjô | Yoshito Chûjô |
 Miho YoshiokaPilot Azusa Kisaragi | Pilot Azusa Kisaragi |
| MMitzuki KogaMechagodzilla Operator Kyôsuke Akiba | Mechagodzilla Operator Kyôsuke Akiba |
 Hiroshi KoizumiDr. Shin'ichi Chûjô | Dr. Shin'ichi Chûjô |
 Tsutomu KitagawaGojira | Gojira |
| MMotokuni NakagawaKiryu | Kiryu |
 Akira NakaoPremier Hayoto Igarashi | Premier Hayoto Igarashi |
 Koichi UedaGeneral Dobashi | General Dobashi |
| TTatsuki OmoriShun Chujo | Shun Chujo |
 Koh TakasugiJSDF Lieutenant Togashi | JSDF Lieutenant Togashi |
 Norman EnglandSgt Woodyard | Sgt Woodyard |
 Yumiko ShakuAkane Yashiro | Akane Yashiro |
 Yûsuke TomoiLieutenant Susumu Hayama | Lieutenant Susumu Hayama |
 Takeo NakaharaJSDF Chief Hitoyanagi | JSDF Chief Hitoyanagi |
 Naomasa MusakaGoro Kanno | Goro Kanno |
| YYasuo KurashikiReporter | Reporter |
 Noriko WatanabeShun's Mother | Shun's Mother |
 Kōji ShimizuIsao Akiba | Isao Akiba |
 Masami NagasawaShobijin | Shobijin |
 Chihiro OhtsukaShobijin | Shobijin |
 Masaaki TezukaScientist in monster DNA repository (uncredited) | Scientist in monster DNA repository (uncredited) |