We try to explain, in theoretical terms, Japan's increasing income inequality in terms of higher education. By examining the relationship between the cost of education and the wage rate, we explain how the link between parents' and their children's educational advancement is strengthened. Given that the wage rate does not increase much, even if the initial education level of the poor is higher than the poverty trap threshold, they cannot attain higher education in the long run because of an increase of the cost of education. A sufficient subsidy for education scholarships can enhance income equality in the long run.