Ryuben (1208-September 14, 1283) was a priest of the Jimon School of the Tendai Sect and waka poet who lived during the middle of the Kamakura Period. His father was Takafusa SHIJO and his mother was the daughter of Mitsumasa HAMURO. His original name was Kokaku. His popular names were Dainagon Hoin, Nyoi ji dono and Shofuku ji dono. He was betto (the head priest) of Tsurugaoka Hachiman-gu Shrine and Onjo-ji Temple, daisojo (a Buddhist priest of the highest order) and Daiajari (Great Ajari). He reestablished the Onjo-ji Temple by linking himself with the Tokuso Family of the Hojo clan and was nicknamed "seiso (politically influential priest) in Kamakura."
In 1220, at the age of thirteen years old, he entered the Onjo-ji Temple and became a priest. His reputation was already high when he was young and, in 1234, he went down to Kamakura for the first time by the invitation of Yoritsune KUJO, who was seii taishogun (literally, great general who subdues the barbarians). In 1237, he became a risshi (Buddhist priest) at the age of thirty years old and on June 23, 1238, he underwent kanjo (a ceremony to be the successor) from Eni. In that year, he was promoted to Shosozu (junior secondary prelate), and then in 1240 Daisozu (the upper Buddhist priests in the second highest position) and, in 1243, he was promoted to Hoin (the highest rank among Buddhist priests) with his merit of incantation for the birth of the Imperial Prince Hisahito (later Emperor Gofukakusa). Even during this period, he often visited Kamakura at the requests of Yoritsune KUJO and Tsunetoki HOJO, who were the Shikken (regents to the shogunate), and spent days to go and return between Kamakura and the Onjo-ji Temple.
However, Miya-sodo (ailed attempt at rebellion) in 1246 and the Battle of Hoji in 1247 changed his fate drastically. This series of disturbances were caused by Yoritsune KUJO and his supporters aiming at overthrowing Tokiyori HOJO, who was Shikken. At that time, since Jien, who was a real younger brother of Kanezane KUJO, assumed the position of Tendai-zasu (head priest of the Tendai sect), the Tendai sect came to have a close connection with the Kujo family, and the Shingon sect also bent before power of the Kujo family which was the kingmaker in the imperial court. Therefore, in a series of incidents, a large number of priests of esoteric Buddhism prayed for the overthrow of Tokiyori. Due to such a situation, only Ryuben came to see Tokiyori at his request and prayed for Tokiyori's victory. After Tokiyori won, the influence of esoteric Buddhism drastically retreated in Kamakura, and the Zen sect launched. Under such a situation, however, only Ryuben built up the confidence of Tokiyori, and obtained support from the Kamakura bakufu (Japanese feudal government headed by a shogun). On August 6, 1247, Ryuben was appointed as betto of Tsurugaoka Hachiman-gu Shrine and stayed in that position until he died.
In 1252, Imperial Prince Munetaka, who had just came down to Kamakura as a new shogun, fell ill, and Ryuben prayed for recovery from illness. After he recovered, Ryuben was not only appointed to gon no sojo (a highest ranking priest, next to a sojo) as a reward, but also began to often visit the Imperial Prince Munetaka and acted as a member of his waka group. Also, on the occasion of the birth of the first son of Tokiyori (later Tokimune HOJO), Ryuben prayed and he was given a shoryo (territory) as a reward.
The ardent wish of Ryuben, who succeeded to make his way into the world smoothly, was the reestablishment of the Onjo-ji Temple. Although the Onjo-ji Temple had been deeply trusted by MINAMOTO no Yoritomo, it lost trust from the shogunate because of the assassination of MINAMOTO no Sanetomo by Kugyo, who had been being trained in the Onjo-ji Temple, and had been being leaving. Tokiyori, who heard Ryuben's request, promised to give support to Onjo-ji Temple and Ryuben established the Nyoi-ji Temple as a branch temple of the Onjo-ji Temple and he was busily engaged in fundraising for it. On March 6, 1260, an imperial sanction for building Kaidan (Buddhist ordination platform) was suddenly given to the Onjo-ji Temple, which was a long-lasted ardent wish. Although it was cancelled three days later because of violent opposition by the Enryaku-ji Temple, it is rumored that Ryuben was in the background.
In 1264, Ryuben was appointed as the Onjo-ji Betto while he lived in Kamakura same as before and, on December 23, 1265, next year, he was promoted to daisojo. In 1267, he was transferred to the Chori (chief priest) of the Onjo-ji Temple and in 1268, next year, he was appointed as Daiajari. During this period, he dared to conduct Jukai (handing down the precepts) using sanmayakai in order to make the previous imperial sanction into an accomplished fact, holding out against the Enryaku-ji Temple under support from the Kamakura bakufu. He also prayed for important matters such as Mongol invasion attempts against Japan and protected the Kamakura bakufu and the Tokuso Family of the Hojo clan in the religious aspect. In latter days of his life, he lived out in the Chofuku-ji Temple in Kamakura and died at the age of seventy-six.
With respect to waka poetry, he positively acted as a waka poet who succeeded in writing waka poetry of the Rokujo family and twenty-five waka of his were adopted in eleven Chokusen wakashu (anthology of Japanese poetry compiled by Imperial command) and many of his waka were adopted in many collections of poems.