The earliest Christian missionary efforts in Japan were those of the Franciscan order, which sent a mission under Mateo Da Rascaña. This mission landed in Nagoya in 1522 and marked the beginning of Christian proselytisation in Japan. Landing in Nagoya in 1522 they were received by Oda Shinjo (織田信定). The Spanish and Portuguese traders in the region had spread Christian ideas, but this marked the first attempt at conversion. They made some progress, managing to convert the daimyo Oda Nobuhiro, lord of Anjo, and brother of Oda Nobunga.
The Jesuit order, founded in 1540, conducted wide reaching and zealous missionary campaigns across India, the Indies and Japan, wherever European trade had recently been established. In Japan they first came to Kyushu, where they were received at Kagoshima. They were granted permission to found a churches and missions at Saiki, Dan no Ura (modern Kitakyushu) and at Nagasaki, by the few daimyos, such as Omura Sumitada, Arima Harunobu and Otomo Sorin, who saw the profit in conversion, by currying favour with the European merchants.
1550-1570 saw competition between the Portuguese and Spanish in the form of sponsorship of different missionaries, the mainly Spanish funded mendicant orders, mainly Dominican and Franciscan, and the Jesuit order, encouraged by John III of Portugal in 1545. This was settled by a Papal Bull in 1575, establishing the diocese of Funai (Nagasaki) under the jurisdiction of the diocese of Manila, itself only established a few years prior.
By 1582, there were around 570,000 practising Christians in Japan, with an estimated total population of ~15,000,000, making about 0.038% of the population Christian. However those converted often comprised the upper classes and daimyo, being targeted particularly by missionaries. The Jesuits believed that it was better to seek to influence people in power and then allow the religion to be passed downwards to the commoners later. They tried to avoid suspicion by not preaching to the commoners without permission from the local rulers to propagate Catholicism within their domains. As a result, several daimyo became Christians, soon to be followed by many of their subjects as the Dominicans and Augustinians were able to begin preaching to the commoners. Between 1553 and 1620, 144 Daimyos were officially baptized, and many more were sympathetic to the Christians.