The first Protestant missionaries came to Japan in the 19th century from the mainline denominations about the time when the Western Great Powers forced the national government to do away with its isolationist policy with their battleships. More missionaries landed in Japan as the country asked for the latest Western knowledge and civilization. The Christians were persecuted in the society even after the abolition of the prohibition on Christianity in 1873. Evangelism, hence, has been successful through Christian institutions, such as private schools and social welfare organizations.
It was in 1941 that the government forced all the Protestant denominations to unite into one. This was the founding of the United Church of Christ in Japan (UCCJ). Most of the former denominations supported by the foreign mission boards, however, spun off after World War II to enact their own confession of faith. Those that remained were the ones related to the United Church of Christ, the Christian Church (Disciples of Christ), the Presbyterian Church (U.S.A.), the Reformed Church in America, the United Methodist Church, and the United Church in Canada.
The UCCJ, as the largest protestant denomination in Japan, boasts 1,700 local churches and 85,000 active members, but now struggles with ageing congregations, the decreasing number of newly baptized (i.e. 1,300 a year) and seminarians, and the increasing number of churches without pastors. God is, however, sending Korean pastors to fulfill this vacancy, simultaneously rebooting the evangelism of the UCCJ, with their vigorous mission spirit and capability to quickly master the Japanese language.