Did the Japanese people establish the Constitution of Japan by their own volition? The debate over the legislative process of the Constitution of Japan has continued. During the occupation of Japan the Supreme Commander for the Allied Powers (SCAP) drafted the Constitution. Did the Americans bestow the Constitution upon the Japanese people, or did they force it upon them? This is why some insist that there is a serious flaw in the Constitution. According to those who make this assertion, the writing style of the Constitution (especially the Preamble) is a literal translation of the English text and sounds unnatural in Japanese. As a result, they support the argument for establishment of an autonomous constitution, which calls for the Japanese people to rewrite their own Constitution. A counterargument against the theory that the Constitution was forced upon the Japanese people is that the Constitution of Japan conforms to the provisions of the Meiji Constitution. It was enacted after being under deliberation in the Diet and then passed by the Diet. Public-opinion polls from that time also indicate that many people welcomed the new constitution. There is also the interpretation that because the Constitution has remained in effect for many years, the sovereignty of the Japanese people has been confirmed, and they actively selected their constitution.
The Constitution of Japan is based on Article 73 of the Meiji Constitution and it was enacted as a revision of the previous constitution. The Japanese government wrote the Revised Draft of the Constitution (Kenpō kaisei sōan) based on SCAP’s draft and the House of Representative and the House of Peers approved it by a majority vote. During that time, the draft was submitted to committees in both houses. Amendments from both SCAP and the Japanese government were also added. Supporters of the argument that the Constitution was forced upon Japan point out SCAP’s restrictions on the freedom of speech. They are therefore skeptical about the validity of the approval by the public and the Diet. In terms of constitutional law, Japan’s acceptance of Article 12 of the Potsdam Declaration, which demanded adoption of the principle of popular sovereignty, is regarded as a legal revolution involving the Japanese people gaining sovereignty. The so-called “August Revolution” theory argues this notion that the Japanese people enacted their own constitution. Miyazawa Yoshitoshi, the constitutional scholar who proposed the “August Revolution” theory, argued against the theory of the limits of constitutional revision which was grounded on the idea that the Constitution of Japan is invalid. According to one interpretation regarding the theory of the limits of constitution revision, changing the Meiji Constitution, which was an "imperially bestowed Constitution" (kintei kenpō), into a “constitution enacted by the people” (mintei kenpō) exceeds the limits of constitutional revision.