Waqtigaas, Mitsubishi waxay ka shaqeyneysay inay kor u qaaddo matoor kale, Ha-42 (hal-abuur 18-silinder ah oo ka yimid Kasei), horumarinteeda ayaa mudnaanta la siiyay Ha-43, dib u dhigista dhammaystirka. Sidaa darteed, Ha-45 ayaa adeegga ugu horeeyay, inkasta oo ay dhibaato ka haysato arrimaha la isku halleyn karo, taas oo sidoo kale dhibaato ku keeni doonta Ha-43. Diyaarado badan oo rajo leh, sida Kyushu J7W interceptor iyo Mitsubishi A7M "Reppu" dagaalyahan, ayaa loo qorsheeyay inay adeegsadaan Ha-43, laakiin ugu dambeyntii, diyaaradaha noocan oo kale ah ma aysan adeegsan ka hor inta aysan Japan is dhiibin
, sidoo kale mashiinka laftiisa ma uusan samayn.