有別於戰後以來政治思想史、歷史與文化的研究，多元主義於 1970 年代中期後在日本政治學界正式登場。利用個案研究、深度訪談與調查計量方法，多元主義針對現代日本政治的運作進行實證分析，而日本的政經與社會結構也出現多元化的現象，賦予多元主義解釋的有效性，使得多元主義研究蔚為日本政治學的新潮流。然而，1993 年自民黨的下野，以及聯合政權形態的常態化，政治決定架構出現重大的轉變，多元主義在此挑戰下，採取政策爭論點研究途徑與特定行為者的個案研究，努力建構普遍的解釋模式，以擺脫特定政黨執政的束縛。此外，日本媒體的詳實報導、政治家的回顧與紀錄、政治學者的深度訪談與整理分析，同樣提供實證研究的重要基礎資料，使得日本政治的實證分析成為可能。

Differs to the traditional approaches of political theory history and the historical-cultural studies in postwar Japan, the pluralism approach had been introduced and connected to Japan’s political studies since the mid-1970s. Because of various changes of political, economic and social structure in Japan, the pluralism approach, which especially emphasizes on the research methods such as case study, in-depth interview and survey study, was efficiently utilized to analyze Japan’s practical politics and gradually becomes a popular academic trend. However, since the LDP lost its power over government in 1993, the coalition cabinet regime as a new replacement to the old decision-making structure has made an obvious change in Japan’s politics. The pluralism approach adequately explains Japan’s decision- making process via research methods of policy-dispute and case study of particular actors. Besides, many fundamental empirical research materials, such as the detailed news reports, politicians’ biographies and academic interview records, are also beneficial for pluralistic scholars to engage in studying Japan politics.