Ayoungboytakeshismother'splaceinagroupofgemstone-basedbeings,andmustlearntocontrolhispowers.　　ThisseriesissetinthefictionalBeachCity,whereagelessalienwarriors,theCrystalGems,liveinanancientbeachsidetemple,protectingtheworldfromevil.Theyprojectfemalehumanoidformsfrommagicalgemstonesthatarethecoreoftheirbeing.TheCrystalGemsareGarnet,Amethyst,PearlandSteven,ayounghalf-human,half-Gemboywhoinheritedhisgemstonefromhismother,theGems'formerleaderRoseQuartz.AsSteventriestofigureouthispowers,hespendshisdayswithhishumanfatherGreg,hisfriendConnie,otherpeopleinBeachCity,ortheotherGems,whethertohelpthemsavetheworldorjusttohangout.Heexplorestheabilitiespasseddowntohimbyhismother,whichincludefusion(theabilityofGemstomergetheiridentitiesandbodiestoformanewandmorepowerfulpersonality).