This paper considers the significance of justice in maintaining local public schools as integrated schools where children in the same area should all attend. Recently, local public schools are not assumed to be the best and only schools by parents while better alternatives including independent schools seem to be available for their children. It is becoming difficult to persuade parents not to opt out of local public schools in the age when parents are permitted and even encouraged to choose by themselves schools suitable for their children. In fact, more than 20% of pupils of the 23 Wards of inside Tokyo do not go on to public junior high schools but to independent private schools. Ulrich Beck called this trend individualization where parents prefer choosing freely over being treated equally regarding the groups in which their children are being educated. Although formally, equal opportunity of education is still assured for every child, substantial inequality prevails between the different learning groups. This paper suggests that substantial equality of education demands parental approval for mutual responsibility in helping all children to attend the same school and to exchange learning resources with each other. John Rawls is well known for formulating two principles of justice: equal freedom and open opportunity. He also made an important distinction between distributive justice and allocative justice. According to Rawls, distributive justice requires sharing the common resources fairly among those who contributed in producing them, while allocative justice only requires assigning the given resources such as national budget to each area and institution according to the need. This distinction is relevant in maintaining local public schools as integrated schools : substantial equal opportunity in education cannot be assured by following allocative justice but by adopting distributive justice, as opportunity in education is a sort of social resources to be produced and observed by people of the same area. The Coleman's Report (1966) is regarded as a typical case proposing educational reform to introduce integrated schools instead of racially segregated schools to every area. Coleman expected children of different cultural backgrounds to exchange their learning resources with each other. But he did not arrange the incentive to exchange learning resources between white and black children before the introduction of integrated schools. Hence quite a few white parents withdrew their children from integrated schools and chose independent schools for their children to be educated among the peer group with similar aspiration. Coleman's conception of integrated schools shows the difficulty of maintaining local public schools for all the children in the same area. On the other hand, some parents do keep their children at local public schools even though they are given the choice to opt out of them. Albert Hirschman called such behavior loyalty and attributed it to these parents' conviction that the existence of public schools is a public goods from which no one can retreat. In conclusion, this paper emphasizes the role of justice to arbitrate the claim for free choice of education and the claim for equal opportunity of education.