Despite Mitsubishi 's close ties to the Japanese military establishment and his direct participation in the nation 's buildup towards the Second World War , Horikoshi was strongly opposed to what he regarded as a futile war . Excerpts from his personal diary during the final year of the war were published in 1956 and made his position clear : On 7 December 1944 , a powerful earthquake in the Tokai region forced Mitsubishi to halt aircraft production at its plant in Ohimachi , Nagoya . An air raid made by B-29s on the Mitsubishi Engine Works in Daiko-cho , Nagoya a week later caused extensive damage to the works and a severe setback in production . Horikoshi , who had been at a conference in Tokyo with Imperial Navy officers to discuss the new '' Reppu '' fighter , returned to Nagoya on the 17th , in time to experience another air raid on the Mitsubishi factories the next day . As a result of the air raid , the company evacuated its machinery and engineers to the suburbs of eastern Nagoya . Horikoshi and the Engineering Department were rehoused in a school building which had been requisitioned
a powerful earthquake
1944 Tōnankai earthquake
Jiro Horikoshi