When Prime Minister Koizumi Junichiro appointed five women ministers to his cabinet, the decision not only surprised the Japanese, but also foreign observers who had criticized the nation for its dearth of women in politics. His appointments increased the representation of women ministers to 22%, the highest in Japanese political history.

Because backlash against the gender equality policy is widespread, it is unlikely that the increase of the number of women ministers resulted from social demand or the rectification of gender inequality in Japan. This paper addresses the question of why, despite the antagonistic political situation in 2001, Prime Minister Koizumi appointed five women to the cabinet. In this paper, I consider the likelihood of the number of women ministers increasing, or at least remaining stable, in the near future. I also discuss those factors that both promote and hinder the appointment of women ministers in postwar Japan, including legal restrictions on appointment and the history and conditions under which women ministers have been appointed in Japan.

The first hypothesis I examine is that the more women there are in the Diet, the more likely it is that the number of women ministers will increase. My analysis indicates that although an increase in women Diet members may help increase the appointment of women ministers, it is neither a necessary precondition for their appointment nor an inevitable consequence of women's increased representation in the two legislative houses.

My second hypothesis suggests that the male-oriented political recruitment process hinders women's ability to be appointed to the cabinet. The data reveal that women Diet members were appointed to the cabinet most often, but there was also a notable increase in the number of women cabinet members appointed in the 1990s and 2000s who were ex-bureaucrats. In general, women Diet members lack the type of political experience, career length, and patronage necessary to secure appointments as ministers. One way for a woman to compensate for these deficiencies is to have experience as a government officer; in fact, women who are former bureaucrats and have strong ties to particular types of organizations are most likely to be appointed to the Cabinet.

My final hypothesis is that if a woman-friendly political opportunity structure exists, the number of women ministers will increase. One such structure might be a left-wing administration, which tends to appoint more women to high status positions than does a right-wing administration. My examination of the political characteristics of the prime ministers and administrations under which women ministers were appointed revealed support for the political opportunity structure hypothesis. I conclude that Prime Minister Koizumi Junichiro was able to appoint five women ministers because he is a minority in the LDP and lacks a strong power base in the party. More importantly, he appointed them as a way to distinguish himself from incumbent LDP representatives and win popular approval as a “liberal” and “uncorrupted” politician.