Abstract: Although the executive branch appoints Japanese Supreme Court justices as it does in the United States, a personnel office under the control of the Supreme Court rotates lower court Japanese judges through a variety of posts. This creates the possibility that politicians might indirectly use the postings to reward or punish judges. For forty years, the Liberal Democratic Party (LDP) controlled the legislature and appointed the Supreme Court justices who in turn controlled the careers of these lower-court judges. In 1993, it temporarily lost control. We use regression analysis to examine whether the end of the LDP’s electoral lock changed the court’s promotion system, and find surprisingly little change. Whether before or after 1993, the Supreme Court used the personnel office to "manage" the careers of lower court judges. The result: uniform and predictable judgments that economize on litigation costs by facilitating out-of-court settlements. Reprinted as a chapter in The Contemporary Civil Law Tradition, edited by John Henry Merryman, David S. Clark & John Owen Haley (2015).