The present article aims to review the research trends on individual differences in personality variables published or reported in Japan in recent years, mainly from July 2021 to June 2022. This article also aims to discuss the current challenges and future perspectives in the area of individual differences research in Japan. In the review of individual differences research, this paper classifies personality variables into two broad levels: basic traits and characteristic adaptations. Previous studies focusing on the individual difference variables included in each level are reviewed, and their findings are summarized.Finally, we discusses the current challenges of a series of individual differences research in Japan for contributing to an integrated and comprehensive understanding of human personality. This study points out the lack of studies on interspecies differences in personality or on the uniqueness of each individual, the lack of focus on interactions, and the fact that basic traits are often not considered in the studies dealing with the characteristic adaptation level variables.