KaiNagisa,anormalhighschoolgirlwhowishestoonedaybecomeaprofessionalwrestler,issuddenlyapproachedbyarobotknownasanIczel.IczelurgeshertohelpsavetheEarthfrominvadingalienscalledGeas.TheGeas,ledbyChaosandCross,arebentonstrippingEarth'sresourcesandthendestroyingit.Tofighttheinvaders,NagisamustmergewithIczelandbecomeabattle-suitedwarriornamed"Iczelion".SheisreluctanttotakeupthissuddenunbelievabletaskandfightwiththeotherIczelionsofEarthbecauseNagisajustwantstoliveanormallifewithouthavingsuchbigresponsibilities.Nagisamustovercomeherfearsandfight,togetherwithotherIczelions,topreventtheinvadingalienforcesfromdestroyingtheirhomeplanet,Earth.