Japanese compulsory education is considered as relatively egalitarian since poorer regions receive more funding from the central government, which standardizes the quality of education nationwide. Nevertheless, the literature indicates socioeconomic status-based achievement and educational attainment gaps. As parts of explanations of these gaps, previous studies have indicated an association between students' socioeconomic status and their study efforts, or inequality of effort. This study is the first to assess this phenomenon while the most critical mass education selection in Japan is approaching, building on relevant theoretical frameworks regarding educational expectations, including anticipatory socialization. To investigate inequality of effort among ninth-grade students, the study also examines the differences between students' neighborhoods on the basis of mechanisms of neighborhood inequalities (i.e., social contagion and collective socialization). Overall, using multilevel modeling with nationally representative data from Japan, this study provides empirical evidence for inequality of effort and the role of post-secondary educational expectations at both the individual and neighborhood levels. This inequality of effort is observed despite the pressure that occurs about three months before the period of selections by high schools. In particular, students from advantaged families and community environments expect to pursue higher education and therefore tend to spend longer hours studying, whereas those from disadvantaged families and communities exert less effort. As Japan is not the only country where the relation between students' socioeconomic status and efforts is evident, this study's results may be applied to other societies to better understand mechanisms of intergenerational transmission of inequality.