Since the 1990s, the Japanese social structure has been changing mainly due to economic globalization. The gap between rich and poor has been widened. The economic policy of the government that tries to introduce the market-competition principle into all sectors in order to revive economic growth is promoting such social change. It seems illusionary that either activating market competition or the reconstruction of the welfare state could revive economic growth. Instead, we should consider a transformation from an industrial to a sustainable society as an inevitable course of social development in the twenty-first century. In 2015, the Japanese Association of the Sociology of Law (JASL) held a symposium entitled “Law and Legal Science in the Transformation to Sustainable Society” during its annual meeting. The main issue was which role legal studies can/must play in such a transformation. I think there are two different approaches. One is to establish the “sustainable principle” as a legal principle like the “precautionary principle” in environmental law. The other approach is to reconsider and reconstruct fundamental legal categories of modern law, which have supported industrial society as its legal infrastructure. This approach will be the subject of the paper. I will deal with the case of property rights to agricultural land.