Under the Japanese Constitution, social rights, as well as civil liberties, constitute important parts of the guarantee of “fundamental human rights.” Article 25 guarantees that all people have the right to enjoy a decent life, which is called people’s rights to live. Because the Constitution is the highest authority in the nation, the protection of the right to live in the Constitution becomes the basis of all governmental policy concerning welfare. For protecting this right to live, Japan’s courts have made many decisions, which force the government to produce welfare policy. The court, therefore, becomes an important role in the process of welfare policy-making. This paper focuses on the guarantee of people’s right to live, and is intended to introduce how Japan’s welfare policy has been influenced by courts from the viewpoints of constitution and policy.