ag awa , ▁TV ▁S ait ama ▁and ▁TV Q ▁Ky ush u ▁Broadcast ing ▁Co ., ▁Ltd . ▁ ▁The ▁adaptation ▁was ▁announced ▁on ▁the ▁prom ot ional ▁sle e ve ▁wrapper ▁of ▁Ga - rei ''' s ▁sixth ▁volume ▁regarding ▁the ▁green ▁light ing ▁of ▁the ▁show . ▁A ▁Ga - Re i : ▁Zero ▁television ▁ad ▁was ▁soon ▁a ired ▁to ▁promote ▁the ▁show ' s ▁up coming ▁release , ▁followed ▁by ▁ 3 0 ▁second ▁commer ci als ▁that ▁were ▁on ▁the ▁Ga - Re i : ▁Zero ▁websites . ▁Origin ally , ▁it ▁was ▁announced ▁that ▁the ▁an ime ▁would ▁be ▁an ▁original ▁story , ▁suggesting ▁that ▁it ▁had ▁nothing ▁to ▁do ▁with ▁the ▁m anga ▁except ▁its ▁setting : ▁however , ▁when ▁the ▁first ▁episode ▁a ired , ▁view ers ▁were ▁confused ▁when ▁the ▁entire ▁main ▁cast ▁was ▁suddenly ▁killed ▁off . ▁It ▁was ▁only ▁later ▁revealed ▁in ▁the ▁second ▁episode ▁and ▁still ▁later ▁in ▁a ▁radio ▁interview ▁with ▁cast ▁members ▁Minor u ▁Sh ira ishi , ▁Ka oru ▁M iz uh ara ▁& ▁Min ori ▁Ch ih ara , ▁that ▁the ▁an ime ▁in ▁fact ▁tells ▁the ▁back st ories ▁of ▁Y omi ▁and ▁K ag ura ▁before ▁the ▁events ▁of ▁the ▁m anga , ▁thus ▁making ▁Ga - Re i : ▁Zero ▁a ▁pre quel ▁to ▁the ▁original ▁Ga - Re i ▁series . ▁ ▁Fun imation ▁Entertainment ▁announced ▁Ga - Re i : ▁Zero '' s ▁English ▁license ▁in ▁August ▁ 2 0 1