Japan is one of the countries that suffered defeat in World War II. Since this defeat, Japan has begun to focus on carrying out economic recovery and eliminating military functions. Then the Fukuda doctrine emerged with the aim of discussing the Japanese view that it would emphasize the use of popular culture as a diplomatic tool with other countries regarding the Southeast Asian region as a former colony. This study will discuss Japan's strategy in developing its popular culture through AKB48 Group in Southeast Asia. The research method to be carried out in this study is a qualitative method with the main sources in the form of literature references, books, journals, official government and organizational reports, and articles from the internet. The results of this study indicate that there are three stages of Cool Japan Strategy as a Japanese strategy in gaining economic benefits from popular culture and the formation of AKB48 sister groups in Southeast Asia to maintain the sustainability of this strategy.