Nichiro (1245-1320) was Nissho's nephew, and he became a disciple of Nichiren Shonin in 1254. Nichiro was extremely devoted to Nichiren Shonin and is often called the "beloved disciple." When Nichiren Shonin was being taken away to Izu, Nichiro charged into the water in an attempt to acompany him. The samurai beat him away with oars which permanently crippled his hand. Nichiro was also arrested at the time of the Tatsunokuchi Incident. He was thrown into a dungeon in Kamakura where he received a famous letter of encouragement from Nichiren Shonin. He later became a favorite of the jailer, who actually allowed him to leave in order to visit Nichiren Shonin on Sado Island. Nichiren Shonin was very touched but also very upset that Nichiro had possibly endangered the jailer and so sent him back. Finally, Nichiren Shonin was pardoned and Nichiro was sent to bring the news. His eagerness, however, almost got him killed. Because he did not stop to rest in the frigid winter weather, he collapsed in the snow and almost died of frost bite. Fortunately, he was found and was able to complete his mission.
Upon returning to Kamakura in 1274, Nichiren Shonin put Nichiro in charge of a new temple at Hikigayatsu, Kamakura. This was the Myohonji Temple. Because it was Nichiro's main base of operations in Kamakura, Nichiro's lineage is also known as the Hikigayatsu Lineage.
Nichiro also started a practice hall at the home of Munenaka Ikegami after Nichiren died there in 1282. In 1288, this became the Honmonji Temple. The adminstrative headquarters of the Nichiren Shu are now located there. For this reason, the lineage of Nichiro is also called the Ikegami Lineage.
Nichiro designated Nine Senior Disciples (Kurosu) to continue his propagation efforts. The nine were: Nichizo, Nichirin, Nichizen, Nichiden, Nichihan, Nichiin, Nitcho, Nichigyo, and Rokei. Of these nine, Nichizo was especially noteworthy for bringing Nichiren Buddhism to Kyoto and gaining it official recognition from the imperial family. He will be discussed later. Nichirin later took over Myohonji Temple and Honmonji Temple. Nichiden co-founded the Hondoji Temple in Hiraga, Shimofusa with Nichiro.