The article examines the question of how rigid the system of social stratification is in Japan, whether it is possible for people to move from lower strata to higher strata, and what factors facilitate or, conversely, complicate this movement. The main attention is paid to the problem of intergenerational mobility, which can be used to judge whether society is becoming more equitable, whether there is inheritance of socio-economic inequality or, conversely, whether there are opportunities for its mitigation in subsequent generations. The factors contributing to social mobility, and, conversely, constraining it, are considered by three parameters of social stratification — income level, social status, level of education. The issue of the influence of the institution of marriage on social mobility is also considered. The article shows that, although the life paths of people belonging to different strata develop differently, nevertheless, Japanese society has institutions that allow a person to overcome the influence of “birth circumstances” and climb up the social ladder. The redistribution of income through the social security and taxation system, as well as a relatively small wage gap between workers of different skill levels, make it possible to keep income inequality at a level that supports social income mobility. The rise of the share of more prestigious professions in the professional structure of the employed and a significant increase in the absolute number of those who have these professions create objective conditions for the movement of thousands of young people to higher status groups. Democratization of the education system and easier access of young people from different social strata to good education raise the chances to move up the social ladder for an increasing number of young Japanese. Finally, the democratization of the institution of marriage, the manifestation of which is an increase in the importance of the level of education when choosing a partner and the lower importance of the question of their social roots, also contributed to the mobility of the social structure. Noting these positive changes, the author, at the same time, highlights the factors constraining social mobility, the main of which is the preservation of the hierarchical structure of the Japanese school and university education system.