The orthodox view or 'rule' of Japanese politics over past decades has been that Japanese leadership is weak and reactive. As such, Koizumi Jun'ichirō, a recent Japanese prime minister, is seen as a great exception to this rule. This article seeks to re-evaluate this orthodoxy in light of wider leadership theory and recent studies on Japanese political leadership. Focusing especially on how assessments of Koizumi's leadership compare to those of previous leaders, it looks at how the literature on Japanese politics has viewed both Japan's political environment and its political leaders. It argues that Koizumi interacted with, not merely reacted to, his political environment. At the same time, he employed a leadership style which, although distinctive, shared important similarities with previous leaders. Accordingly, he was less an exception to this rule than a confirmation of the historical diversity of Japanese political leadership.