Shobo (832 - July 30, 909) was a Shingon Sect priest in the early Heian period. He was the founder of the mountaineering asceticism of Tozan School. His secular name was Prince Tsunekage. He was a sixth generation-descendent of the Emperor Tenchi and his father was Prince Kadona. His shigo (a posthumous name) was Rigen Daishi.
He studied under Shinga, Kukai's biological brother. Shobo studied the doctrine of Shingon Esoteric Buddhism (Shingon Sect), traveling to Nanto (southern capital (Nara)) to study the doctrine of Mahayana Buddhism (Sanron Sect, Hosso Sect and Kegon Sect). While his mentor, Shinga had importance for intercommunion with aristocratic society, Shobo kept himself detached from the society. He was known to live a clean life and have a faultless and doubtless character. The differences even suggested that there was a conflict between Shinga and himself. Shobo's following activities were thought to form a marked contrast to Shinga's behavior: Shobo conducted mountain ascetic practices on Mt. Kinpu in Yoshino, and, by adoring EN no Gyoja (A semi-legendary holy man noted for his practice of mountain asceticism during the second half of the 7 century) in his heart, revived the mountaineering asceticism training in Mt. Omine, which was thought to have been abandoned after the disappearance of EN no Gyoja.
Shobo received Jumyo Kanjo (a water rite to be a disciple) and Muryoju-ho (teachings of Sutra of Immeasurable Life) from Shinga. After his mentor's death, he climbed up Mt. Koya at the age of 49, and received a secret art of both the vajra (the Diamond Realm) and garbha (the Womb Realm) mandalas from Shinzen, Shinga's disciple. He received denpo-kanjo (the consecration for the Transmission of the Dharma) from Gennin of Nanchiin of To-ji Temple at the age of 53, was given the position of Ajari (a master in Esoteric Buddhism; a high priest) to became the head of Shingon Esoteric Buddhism succeeding Kukai at the age of 56. Shobo founded Daigo-ji Temple in Yamashina, Kyoto (present day, Yamashina, Fushimi-ku Ward). He also made a base of San-lun (Three Shastras) Teachings by establishing Tonanin Temple in Todai-ji Temple, which should not be overlooked by the two following viewpoints; Shobo's high evaluation of Chugan (Intermediate) or Hannya-ku (the truth that nothing is substantial, void, taught in the Heart Sutra) and Kukai's adjusting ceremonies to Shingon Esoteric Buddhism at major temples at Nanto. Shingon Esoteric Buddhism itself developed based on the doctrine of the Kegon-kyo (Avatamsaka Sutra). In other words, from the fact that the Kegon (a thought of virtues are correctly provided due to trainings and performing acts of charity) doctrine was placed not as the eighth (Tendai Hokke) but as the ninth Jushin (stages of Mind Development) in Himitsu Mandala Jujushinron (Ten Abiding Stages on the Secret Mandalas), Juju taimo (endlessly interconnected net of Indra) (unobstructed) of Sokushin Jobutsu gi (Principle of Attaining Buddhahood with the Present Body) can be thought to have developed into a theoretical foundation of practical code based on the philosophy which symbolized the Kegon doctrine of Ichi-soku-ta and Ta-soku-ichi (one is equal to many, many to one). It is very meaningful that Vairocana, who had been considered a silent existence, described as "this world is Buddha's body (rokudai),"declared that he, himself would preach. In Esoteric Buddhism faith, which puts strong emphasis on measures, moving from theory to practice should be approved from the viewpoint of Mahayana Buddhism prosperity. It should be interpreted that because of the idea, Shobo, recognizing that he was in a direct line of Kukai, the founder, promoted activities at Todai-ji Temple. It should be noted that Mandala, itself, is based on the Kegon-kyo doctrine, "the integral of Fugen Bosatsu's trainings."
Shobo served as betto (steward) of Kegon Sect of Todai-ji Temple and To-ji choja (the chief abbot of To-ji Temple), and so on, and studied both Exoteric Buddhism and Esoteric Buddhism. Ningai, the founder of the Ono School of Tomitsu (Shingon Sect's esoteric teaching), established Mandala-ji Temple at Ono, Yamashina and founded the base for Esoteric Buddhism's practice, and Kancho, younger than Yakushin, who received the kanjo (a ceremony to be the successor) from Emperor Uda at Omuro-Ninna-ji Temple, founded the Hirosawa School of Tomitsu and established Hensho-ji Temple along the shores of Hirosawa-no-ike Pond, and others are thought to have been successors in practical training and contrasted with Shobo, however, it should be interpreted that Shobo as well as the Hirosawa School of Yakushin made important foundations in Shingon-ji Saho Bunryu (branch schools in manners of Shingon Sect), which was later called Yataku Sanjuroku-ryu (thirty-six schools of yataku (Ono School and Hirosawa School)).
It was recorded that Shobo admired both Nyoirin Kannon (the Bodhisattva of Compassion) and Juntei Kannon, ran rites and festivals for them at Mt. Kasatori, also known as Kami Daigo, and prayed for the births of the Emperors Suzaku and Murakami. The belief was also traditionally maintained that Nyoirin Kannon was the incarnation of Seiryo Gongen (A protective god associated with the Chinese temple Ch'ing-lung), who accompanied Kukai when he came back to Japan.
Kangen, the first zasu (head priest) of Daigo-ji Temple, was considered to be Shobo's legal child, who accompanied by Junyu, his disciple, dedicated Kobo Daishi-go title to Oku no in (inner sanctuary) on Mt. Koya, and intended for the prosperity of the post-Kukai Shingon organization.
Shugendo (Japanese mountain asceticism-shamanism incorporating Shinto and Buddhist concepts) in Tozan School, which Shobo was founded, is thought to demonstrate profound preaching by Dainichi Nyorai with Funi Ichijo (most important of the Shingon principles which states to climb the mountain of Ichijo (truth), Mt. Omine, and pray for obtaining the body of funi (a thought that Ri (the innate reason) and Chi (knowledge) are non-two)), which was expressed through "Shugen Ein So Mandala" (literally, mandala of Shugendo under the teaching of Ein (Dainichi Nyorai's most secret teachings)). Generally speaking, it is known that the preaching of Dainichi Nyorai should be developed and grasped through both the vajra (the Diamond Realm) and garbha (the Womb Realm) mandalas, whether in so-called "dai (Great Mandala) (hoshin (Buddhism's highest form of existence) Dainichi), san (sanmaya mandala) (imitsu (mystery of mind)), ho (Buddhist Law Mandala) (kumitsu (esoteric speech)), katsu (katsuma mandala (action mandala)) (shinmitsu (bodily mystery))" panorama, which are related with Ri and Chi of Esoteric Buddhism world, or in both a pluralistic perspective including rokudai (six great elements; that is Dainichi Nyorai) (tai (body)), shiman (four mandala) (so (match)), sanmitsu (three mysteries) (yu (function)), and a general perspective of Juju taimo (unobstructed) (Sokushin Jobutsu gi), but in the viewpoint of mountaineering asceticism, the Japanese animistic belief in holy spirit, it should be noted that Shobo, at this time, exhibited the Ri and the Chi in a monastic way. This happened before the parallel mode of expression, "Kongokai (Diamond Realm) or Taizokai (Womb Realm)," became remarkable after Kakuban Kokyo Daishi in the latter Heian period, and should be understood as an epoch, regarding the religious beliefs particular to the Japanese, in conducting and discussing each master's standpoint or background related with Nini-Funi (also known as Funi-Nini (two sides of the same coin)) in which Oei no Taisei (Perfection in Oei era) reached the summit, more over in the Japanese intellectual history of Esoteric Buddhism, especially practicing or considering Jikyo niso (Jiso (method to practice the doctrine) and Kyoso (logical study of doctrines)).
The term, "Jisshu Jissho" (Discipline to prove the teaching) left by Shobo, should be the mind of mountaineering asceticism and always maintained by practitioners of Tozan School in the process of practice. "Saisho Ein Sanma Yaho" (Dainichi Nyorai's most secret teachings) (Ein Kanjo (the ceremony to be the successor of a ritual of the Ein School))," the base for practice, was the realization of "Richi funi Kai Kai Raisan" (worship of the Shingon conceptual world with the nonduality of knowledge and principle) and it is said that it was given not only to Kangen, his legal child, but also to Teisu at Hokaku-ji Temple, Shingonin, Yamato tosu. Ein Ho (ritual) of Tozan School is also called Bujuho (practice on the mountain) School because of Rei sojo (initiation in an unseen and wondrous method) by Ryuju Bosatsu and is sometimes contrasted with Buchuho (practice on the mountains) School of Honzan School, however, it can be said that the main point common in both schools is to put the priority on practice; practitioners of austerity completely give up any meaningless discussion based on worldly words and thoughts; they only concentrate on practice in mountains or in training halls near which people live. This is connected with following the teaching of Ryuju Bosatsu, the master of Chukan School of Mahayana Buddhism, who tried to reach directly the truth of Hannya-ku through mystic instinct. The practice of prayer directed to pure bodhisattva's spiritual awakening which is opened by Richi funi Raisan is done in order that the prayer recognizes that he or she is in a direct line of Shingon's third founder, Naagaarjuna (Ryuju), and at the same time, the practice is connected to the belief in and assurance of Shingon Esoteric Buddhism, which exists so as that its believers try to realize rishu (the Principle of the Perfection of Wisdom) of bettoku (Distinguished virtue) Buddhas and Bodhisattvas, which all are made from Dainichi Nyorai as Fumon Sotoku (all virtues of Universal Gateway).