Christian has taken root in South Korea. In China, despite bans against foreign missionaries, there are still tens of millions of Christians. I don't know very much about Japan.

Missionaries were definitely sent to East Asia. St. Francis Xavier went to China. The Taiping Rebellion was led by a Chinese man who viewed himself as Jesus' brother.

China has a long history of institutional violence against Christians. A law was created in 1826 which made preaching Christianity to Chinese people punishable by death. Christians were also arrested during the Cultural Revolution.