Since inauguration in 2012, Japanese PM Shinzo Abe made official visits to many states actively. It is worth noting that Abe's first stop was in Southeast Asia and in a press conference at Indonesia, Abe not only announced the Five New Principles for Japanese Diplomacy but also claimed Japan-ASEAN relations as the "most important pillar" of Japanese foreign policy. Since the end of WWII, Southeast Asia has played an important role in Japanese foreign policy. Under Abe, Tokyo has continued the policies of the preceding administrations and devotes strong priorities to Southeast Asia. This article discusses and analyzes Japan's policies in Southeast Asia in recent years. This article first reviews the changes in Japan's Southeast Asia policy before discussing the strengthening of the US-Japan alliance and its implications for Japan's foreign policy in Southeast Asia. The remaining discussion then centers on Japan's national interests, foreign policy actions and future prospects concerning Southeast Asia.