This study interprets the intentions behind the policies from Ikeda’s perspectives on man-agement, and conducts comprehensive evaluation of the reform of the Mitsui Zaibatsu, opin-ion about which is by no means considered settled. In conclusion, the study essentially sees the start towards the modernization of the Mitsui Zaibatsu management─whereby Seihin Ikeda, with criticism of the zaibatsu as leverage, persuaded the Mitsui group and directed substantial zaibatsu reform, i.e. organizational reform of the Mitsui Zaibatsu based on ‘sepa-ration of ownership and management’─as the actual state of the reform of the Mitsui Zai-batsu.
Whilst there is a ‘theory of reform’ regarding the various Mitsui ‘reform’ policies, when evaluating the significance of the ‘zaibatsu switch’ in terms of business history, this opinion is rivalled by a decidedly strong ‘theory of disguise’ and it is believed that a compre-hensive evaluation has by no means been settled. This is believed to be because the Mitsui ‘reform’ ended incomplete, hindered by the insularity of the Mitsui group and the transition to the wartime regime. There are both sides of situational strategy and ‘reform’ amongst the five Ikeda policies, and opinion may be divided based on how one interprets the inten-tions behind the policies of Seihin Ikeda, who led the reform of the Mitsui Zaibatsu.