Nichio (July 5, 1565 - April 22, 1630) was a Nichiren sect priest from the Azuchi-momoyama to the early Edo period. He was born in a family of kimono fabric dealers in Kyoto. His Azana (popular name) was Kyoei. His pseudonym (pen name) was Ankokuin or Busshoin. He was the founder of the Fujufuse school.
In 1574, Nichio learned doctrine of the sect under Nitten at Myokaku-ji Temple (Kyoto City) (Kyoto Prefecture). In 1595, Nichio opposed to Jufuse school, including Nichiju in Honman-ji Temple (Kyoto City) (Kyoto Prefecture) about whether they should attend Senso kuyoe (ceremony of thousand priest mass) at Hoko-ji Temple Daibutsu-den Hall, which was hosted by Hideyoshi TOYOTOMI. Nichio left Myokaku-ji Temple (Kyoto City) (Kyoto Prefecture), insisting on Fuju-fuse-gi (nothing could be received or given), and lived in seclusion in Koizumi, Tanba Province. In 1599, Nichio didn't attend the Kuyo-e (memorial service), which was hosted by Ieyasu TOKUGAWA and was exiled to Tsushima Island due to Osaka tairon. In 1623, after spending thirteen years in Tsushima, Nichio was pardoned and the gutsu (missionary activities) of Fuju-fuse-gi was allowed. In 1630, the conflict between the Jufuse school and the Fujufuse school was reignited. The two schools had a debate (Shinchi tairon) at the Edo-jo Castle, and Nichio was taken as the leader of the Fujufuse school, which was considered to rebel against the Bakufu and sentenced to be again exiled to Tsushima Island. However, since he was already dead, his bones were taken to Tsushima Island.