For a long time mainstream proponents of coalition theories have neglected Japanese politics because of its “uncommon” one-party dominant regime. However, since 1993, party politics in Japan has entered into a new era of coalition politics. Unfortunately, only a few coalition theorists and experts on Japanese politics have tried to analyze this new reality. To bridge these theoretical as well as empirical gaps, this study examines two coalition governments in Japan that formed after the 1993 general election. After reviewing contending approaches and unified models of coalition government, some explanatory limits of coalition theories are addressed, and some modifications to them are proposed to accommodate the Japanese experience.