Ayukawa, a well-connected and aggressive risk taker, also made himself a principal partner of the Japanese Colonial Government of Manchukuo. Ultimately, Nissan Heavy Industries emerged near the end of the war as an important player in Japan's war machinery. After the war ended, Soviet Union seized all of Nissan's Manchuria assets, while the Occupation Forces made use of over half of the Yokohama plant. General MacArthur had Ayukawa imprisoned for 21 months as a war criminal. After release he was forbidden from returning to any corporate or public office until 1951. He was never allowed back into Nissan, which returned to passenger car manufacture in 1947 and to its original name of Nissan Motor Company Ltd. in 1949.