Christianity was introduced to Japan in the 16th century, when people in Japan believed in Shinto and Buddhism.
Christianity spread to Japan for about 60 years, because Japanese political leader Nobunaga Oda was enterprising and was not uncomfortable with Christianity. However, the military commander who took over his politics severely banned Christianity. This situation lasted for about 260 years.
During this period, Christianity did not disappear. People pretend to be Buddhists to the government and maintained Christian traditions. “Nagasaki/Amakusa area” is famous as a UNESCO World Heritage Site
Although it is not well known, there is a traditional Christian village in Osaka. There is also a small museum, Ibaraki Municipal Christian Relics Depository, which was reformed from a Christian’s house. They say that only the Lord and his eldest son knew about Christianity in the family, so that the government could not find it.