Nichiren-shū
Nichiren Shū (日蓮宗, Nichiren-shū, Nichiren School) is a confederation of four of the original Nichiren Buddhist Schools that date back to Nichiren's original disciples, and part of the fifth:
the Minobu-School (founded by Nikō)
the Hama-School (founded by Nisshō)
the Ikegami-School (founded by Nichirō)
the Nakayama-School (founded by Nichijō (Toki Jōni))
the Fuji-School (founded by Nikkō; part only, some of the Fuji-School belongs to Nichiren Shōshū)
The school's Head Temple, Kuon-ji, is located on Mount Minobu where Nichiren lived in seclusion and where he asked to be buried. Another important temple of Nichiren Shū is Ikegami Honmon-ji where Nichiren died. Its temples have many of Nichiren’s most important personal artifacts and writings (which are considered National Treasures of Japan) in their safekeeping.
Overview of Nichiren Shū
Nichiren Shū does not believe Nichiren designated a single successor, as taught for instance by Nichiren Shoshu, but that he designated Six Senior Disciples to succeed him. The Six Senior Disciples designated by Nichiren were: Nissho (1221-1323); Nichiro (1245-1320); Nikko (1246-1333); Nikō (1253-1314); Nitchō (1252-1317); and Nichiji (1250-unknown).