Christian social reformer, author, and leader in Japanese labour and democratic movements who focused attention upon the poor of Japan.

As a youth Kagawa enrolled in a Bible class to learn English and was soon converted to Christianity. He continued his Christian studies in Japan and the United States. When he returned to Japan he became involved with the labour movement and with social welfare work, choosing to live in the slums of Kōbe. He took part in the campaign for universal adult male suffrage, which was achieved in 1925, and helped organize the Japanese Federation of Labour. In 1921 and again in 1922 he was briefly imprisoned for his labour activities. After his release he began to conduct great evangelistic campaigns in the chief cities of Japan and other countries.

A pacifist, Kagawa founded the National Anti-War League in 1928 and in 1940 was arrested for apologizing to China for Japan's attack on that country. A year later he was one of a group that went to the United States in an attempt to avert the coming war. He returned to Japan after World War II and led the effort to gain suffrage for women.

While in prison in 1921 and 1922 Kagawa wrote his first two novels, Crossing the Deathline and Shooting at the Sun; both became best-sellers. Altogether he wrote more than 150 books, including several novels, such as Before the Dawn (1924); sociological studies and religious studies; and translations of the works of Albert Schweitzer.