The number of adherents to Jodo Shinshu grew for two centuries while troubles of many kinds pounded Japan, particularly beginning in the mid-15th century. Earthquakes in 1447, plague in 1449, smallpox in 1452, riots demanding just government in 1454 and 1457, famine in 1460 and 1461, and revolt in 1462 increased the sense of disorder. The Onin War in 1467 started with a dispute about who would be Shogun, the military strongman of Japan. Two armies of about 100,000 men each fought for 10 years with Kyoto as the battleground, and the city was destroyed. Disasters over succeeding decades led to more civil wars that culminated in 1536 with the destruction of the Nichiren sect in Kyoto by the Mount Hiei Tendai army, which burned 21 temples and killed thousands of priests. Most Japanese were poverty-stricken and desperate for hope, but Buddhism was corrupt and Shintoism largely a relic.
Then came Christianity's reentry into Japan. Portuguese traders arrived in 1543 and Spanish Jesuit missionary Francis Xavier followed in 1549 with two companions. He found to his surprise that "the Good News was already preached" in Japan. It's not clear whether he was referring to remnants from early Christianity or was astonished, as his associates were, by the Jodo Shinshu emphasis on faith in a supernatural power. Others among the Catholic missionaries were depressed by the Jodo Shinshu emphasis on faith alone. One exclaimed that the Lutherans must have gotten there first, and another said that Jodo Shinshu was a Satanic counterfeit.
Xavier pushed on regardless, challenging Buddhist priests to public debates and denouncing what he labeled the three greatest Japanese sins: idolatry, sodomy, and abortion. (Many Christians were caustic about the homosexuality that they said was common among Buddhist monks.) Xavier also used some Japanese words that made listeners think that Christianity was a more virtuous form of Buddhism: He used the word daido-ji (Buddhist temple) for church, so (Buddhist monk) for priest, and jodo (Pure Land) for heaven. Some of his hearers at first even thought he was inviting them to join a new variety of Jodo Shinshu.
Xavier went off to the Philippines and died there, but Christian opportunity in Japan increased as Buddhism continued its decline. In 1571 Japanese strongman Oda Nobunaga decided that his forces were powerful enough to take on the Mount Hiei Buddhist army. Nobunaga's soldiers assaulted the temples and burned all 3,000, killing thousands of Tendai defenders. Nobunaga openly opposed Buddhism and favored the missionaries, seeing them as a counterweight to the Buddhists and hoping they could get him advanced weapons from the West.
Jesuit missionaries ignored peasants and worked to gain the allegiance of daimyos (local feudal lords), pressing them then to ban other religions in their territories and give inhabitants a be-baptized-or-leave order. By 1580 six daimyo had undergone baptism and ordered their serfs to go through the rite as well. Baptismal stats looked great in reports that missionaries sent home to Spain and Portugal: some 50,000 by 1580, perhaps an additional 100,000 by the end of the century.
Belief, though, generally did not go deep. Missionaries emphasized gorgeous altars, sensuous worship, and chanting with incense not unlike that at Buddhist services, so some Japanese agreed readily to be baptized but had little understanding of Christianity. Instead of explaining to Jodo Shinshu believers that their emphasis on faith was right, but that they were putting faith in the wrong place, priests tried to convince the Japanese that the road to heaven was through performance of Catholic rituals.
Furthermore, some missionaries encouraged a simple transference of names. Roadside shrines to Kannon, the Buddhist goddess of mercy, instantly became shrines to Mary. Other Buddhist statues underwent similar relabeling. Christian objects and customs became fashionable, and some Japanese wore crucifixes and "learned by rote the litanies of Pater Noster and Ave Maria." They would recite these prayers in the streets, according to one observer, "because they think it is a good thing and one which will help them to achieve prosperity in worldly things."
The top-down, surface-level approach to church growth seemed to work for a while. More daimyo joined what looked to be the wave of the future. By the end of the 16th century as many as 3 million Japanese out of 10 million were under the control of Christ-professing daimyos. Some missionaries had the newly baptized burn down Buddhist temples and erect churches in their place.
But a movement that lives by decree rather than one-by-one conversion can die the same way. One of Nobunaga's officials assassinated him in 1582, and although Christian influence continued to expand for 15 years, relying on Nobunaga and his allies turned out to be an error. Japan's new autocrat, Hashiba Hideyoshi, was so ugly that he was called "Mr. Monkey" behind his back, but he was also smart. He asked the Spanish and Portuguese tough questions, particularly about their nations' penchant for slave-trading and taking over countries like the Philippines.
Hideyoshi, like his predecessor, may at first have seen Christianity as a way to douse Buddhist power, but he soon stopped worrying about apparently waning Buddhism and started to fear the new religion that was becoming very powerful very fast. He gave Tendai Buddhists permission to rebuild Enryaku-ji, which soon came back to life with 125 temples. In 1587 Hideyoshi ordered (during a night of orgy, Christians said) all 137 Catholic priests to leave Japan, and in 1591 he prohibited any expression of Christianity. Hideyoshi did not enforce those edicts until the Spanish galleon San Filipe ran aground in 1596. His men confiscated its rich cargo, including lots of ammunition, and also interrogated the ship's pilot, who said that Spanish missionaries often preceded military conquest.