The Japanese personal information protection systems began with the establishment and enforcement of the regulation regarding protection of personal information by some local autonomous entities in the mid-70s. Since then, inspired by the OECD`s guidelines, Japanese government consolidated the personal information protection systems with emphasis on public sectors. But with the rapid development of IT society and the expansion of the international information circulations, such adverse effects of the IT society as privacy infringements have become major concerns. Accordingly, in order to balance the protection and the use of personal information, Japanese government tried to establish the personal information protection systems in the private and public sectors. In the mean time, personal information has different merits for different agents. It has personal values for individuals, the supplying party of personal information, while it has commercial or public values for the enterprises or public organizations, the demanding party of personal information. For the participants of the personal information market, the positive effect of using personal information is greater than the negative effects. On the other hand, the negative effects of using personal information are generally determined by the level of personal information protection. Therefore, changes in the personal information protection levels influences the price and the volume of supply and demand. In case of Japan, obvious dead angles of personal information protection have not occurred thanks to the consolidation of the personal information protection regulations. But there exists difference in the prices of personal information due to the existence of the personal information protection gaps in accordance with the sensitivity of the personal information. This causes the differences in the scales of the economic damages caused by the personal information leakages.