Tachikawa-ryu school (a school of Esoteric Buddhism founded by Ninkan) (立川流 (密教))
The Tachikawa school is also known as the Shingon Tachikawa school.
The scripture of the Tachikawa-ryu school is called Hannya Haramita Rishubon, which is commonly known as Rishu-kyo (Principle of Wisdom Sutra). The school venerates Dakiniten as the God. Buddhism generally prohibits sexual intercourse, following the doctrine of no sexual misconduct. In Esoteric Buddhism, however, Rishu-kyo based on Yoga Tantras (scripture about controlling mind and body) and many Anuttara (supreme) Yoga Tantras accept sexual intercourse. Their creeds are understood as the state of Sokushin Jobutsu (attaining Buddhahood with the present body) realized through sexual intercourse. Although many Yoga Tantras were introduced and spread around Japan, Anuttara Yoga Tantras, which specifically dealt with sexual intercourse, were only partially introduced. Therefore most Esoteric Buddhism schools, excluding the Tachikawa-ryu school, frown upon sexual intercourse.
Especially its principal objects of worship are skulls, of which there are several kinds including ogashira (a big head), kogashira (a small head) and gachiringyo (a head round as the moon). The skulls to be made into the principal object of worship must be as follows. A skull of a person of high rank such as a king or a parent. A skull which has no sutures. A collection of the top part of the skulls of 1000 people (called sencho [a thousand of tops]). A skull selected through a ceremony called hokkairo. The skull is selected in a method previously mentioned, on which surface, coated with harmony water (a liquid made up of a mix of semen and female bodily secretion produced during sexual intercourse) thousands of times. Using the liquid as glue, gold or silver leaves are stuck on the skulls, further a talisman is placed inside it. A Mandala (Buddhist visual schema of the enlightened mind) is painted on the skull which is then padded out and a wide variety of delicacies are offered. In addition you have to keep having sexual intercourse in front of the principal object, and chant a mantra during the religious exercise. In this way it takes about seven years for the skull to become the principal object of worship. It is believed the skulls, depending on their rank, reveal three different effects. It is believed that lower rank skulls grant any wish, middle rank skulls give an oracle in a dream and higher rank skulls tell all the truths in the whole universe.
However there lies another truth behind this licentious ritual. Rishu-kyo explains that things are primarily accomplished only with the existence of the yin yang of men and women. The ritual takes seven years because the goal of the ritual is for a monk and his female partner to reach enlightenment during the course of it. Once they reach enlightenment the skull principal image is not necessary anymore.
The essence of the Tachikawa-ryu school is that a man and a woman become one with Dainichi Nyorai (Mahavairocana), which is the principal image of the Shingonshu sect, through sexual intercourse.
In this point, the Tachikawa-ryu school differs from other existing religious schools which explain that 'women are unclean beings and cannot become the Buddha.'
Tachikawa-ryu school uses the special vajra, of which an end has three blades and the other two blades. This vajra is called warigokosho (five-blade split vajra).
The creed of the Tachikawa-ryu school itself consists of the extended doctrines of Shingon Esoteric Buddhism using the two ways of yin and yang. Tachikawa-ryu school regards the state of male and female copulation as the state of sokushinjobutsu and a figure of male and female copulation is drawn in the form of a mandala. However its rituals, such as having a skull as its principal image, are just popular beliefs. Almost all of the literature describing the secret ceremonies and rules of the Tachikawa-ryu school were lost through book burning. All existing literature about the Tachikawa-ryu school was written by its opponents and therefore it is impossible to know if it describes the truth or not.
A state of male and female copulation, that is, orgasm, came to be considered as the state of sokushinjobutsu for several reasons. Esoteric Buddhism has the thought that human beings are originally not tainted (hongaku philosophy [all living things have an innate ability to achieve enlightenment]). Rishu-kyo also includes the phrases as follows.
An ecstasy in intercourse between a man and a woman is a pure state of Bodhisattva.'
It is also a pure state of Bodhisattva that lust functions tempestuously as if an arrow flies.'
It is also a pure state of Bodhisattva for a man and a woman to have intercourse and enjoy the sensation of ecstasy.'
It is considered that the creed of the Tachikawa-ryu school originates from the sermons about 17 pure states which say that all human activities, including sexual intercourse, is essentially pure.
The Tachikawa-ryu school is said to be a heresy which belongs to Tomitsu (Esoteric Buddhism of the Shingonshu sect). On the other hand, Taimitsu (Esoteric Buddhism of the Tendaishu sect) also had a school called Genshi Kimyo-dan which regarded sexual intercourse between a man and a woman as the state of becoming Buddha. Thus these two are often discussed in comparison with each other.
It is said the Tachikawa-ryu school was founded in the Kamakura period by a monk of Esoteric Buddhism, Ninkan, and perfected in the period of the Northern and Southern Courts by Monkan who became the gojiso (a priest who prays to guard the emperor) to Emperor Godaigo.
In 1113 Ninkan, who was serving Imperial Prince Sukehito, the third prince of Emperor Gosanjo, as his gojiso, attempted to assassinate Emperor Toba but failed.
(This event is called the 'Senjumaru Incident,' after the name of a young servant who was considered to be the actual executioner of the crime.)
In November Ninkan was banished to Ohito, Izu.
(However some say he was the victim of a false accusation.)
Changing his name to Rennen, Ninkan preached Shingonshu sect in this place and met an onmyoji (master of yin yang), Kenren (written as 見蓮 or 兼蓮) from Tachikawa City, Musashi Province. In addition Ninkan met three monks, Kanren, Jakujo and Kansho and initiated them into the secret arts of Daigo Sanboin school.
It is believed that after Ninkan committed suicide by throwing himself from Mt. Jo in April, 1114, Kenren and others established the Tachikawa-ryu school by mixing the yin yang philosophy and the creed of Shingon Esoteric Buddhism and propagated it. The Tachikawa-ryu school was introduced into Kamakura by Shingyo TENNOJI, who was banished from Kyoto, and others.
After that, the Tachikawa-ryu school continued to expand. According to "Juho Yojin-shu" (the oldest book which criticized the Tachikawa-ryu school), 90 percents of the monks of Shingon Esoteric Buddhism became believers of the Tachikawa-ryu school.
At the end of the Kamakura period, Monkan, who had learned the secrets of the arts of the Tachikawa-ryu school from Dojun, a monk in Hojo-ji Temple, had a reputation as 'the most effective man.'
Emperor Godaigo heard this and took Monkan into his service as his gojiso. Monkan initiated Emperor Godaigo into the secret arts and became Gonsojo (the lowest grade that can be held by one who has reached the highest rank in the hierarchy of Buddhist priests) in Sanboin, Daigo-ji Temple. The fact that the emperor embraced the religion meant that Monkan gained a great supporter.
In 1322 Monkan offered a prayer for safe delivery when Kishi, chugu (the second consort of an emperor) of Emperor Godaigo, became pregnant. However this prayer also intended to kill with a curse the regent Takatoki HOJO in power and therefore Monkan, incurring Takatoki's anger, was banished to Io-jima Island, Kagoshima.
In 1331 the Genko Incident broke out. Emperor Godaigo, who failed to overthrow the shogunate, was caught and banished to Okino-shima Island. However in 1333 the shogunate was successfully overthrown as outlaws and powerful shogunal retainers took up arms against it one after another. Consequently Monkan returned to Kyoto and was promoted to the position of Ichi no Choja (highest-ranked chief abbots of the temple) of To-ji Temple.
In response, monks in the Mt. Koya, who professed to be the mainstream of the Shingonshu sect, regarded Monkan as dangerous and in 1335 they oppressed the Tachikawa-ryu school on a big scale. Many monks of the Tachikawa-ryu school were killed and their books were burnt to ashes. Monkan was deprived of the position of the Ichi no Choja, expelled from Kyoto, and sent to Kai Province. After that Monkan followed Emperor Godaigo who founded the Southern Court in Yoshino, and acted secretly with the aim of restoring direct Imperial rule.
After the Gonancho (Second Southern Court) declined, the Tachikawa-ryu school also gradually declined to be extinguished because of oppression in the Edo period. It is an established theory that the Tachikawa-ryu school didn't continue to the present day. Orthodox schools of the Shingonshu sect made an attempt to make their religious precepts stricter to contradict this heresy.
However its peculiar creed had a huge amount of influence on different sects of Buddhism and it is an indirect but nevertheless and important cause of the later development of Esoteric Buddhism thought in Japan.
Many researchers are doubtful about the history mentioned previously.
Literature such as "Dento koroku" (A biography of high ranking monks in Edo period) includes the description that Ninkan initiated the Tachikawa-ryu school. However many errors and inconsistencies are pointed out about the description in "Dento koroku" and it is less reliable.
Ninkan died in Izu five months after being banished there. No prominent act to establish an original theory by Ninkan is seen before he was banished. Therefore it needs to be considered that Ninkan developed the creed, and then further initiated to people in these five months. However it is unlikely as the period is too short. Even supposing that Ninkan had been studying when he was in Daigo Sanboin Temple before going into exile, still there was a too short period for him to initiate Kenren into the secret arts.
Only two people, Ninkan and Senjumaru, believed to be the executioner, were punished following the Senjumaru Incident.
Isn't it because there was no attempt to assassinate the emperor in the first place?
That is, the rebellion was fabricated by the Retired Emperor Shirakawa in order to weaken the influence of Imperial Prince Sukehito and his supporter, the Murakami-Genji (Minamoto clan; Ninkan was a member of the clan as well).
Wasn't it enough to 'sacrifice' these two to achieve the goal, rather than stamping out all of them?
(Some consider that the Tachikawa-ryu school was used as the excuse to highlight Ninkan's evil and he was made out to be a founder.)
Some also believe that Monkan was associated with the Tachikawa-ryu school in order to give the impression that he was a villain.
It is said that the Tachikawa-ryu school was regarded as a heresy taking a cue from Yukai, who accomplished learning of religious doctrines in Mt. Koya, and who criticized the Tachikawa-ryu school, collected books on it in front of Goei-do Hall (hall dedicated to the sect's founder) on Mt. Koya and burnt them. Yukai also banished nenbutsu (Buddhist invocation) which had been held in Mt. Koya. The Tachikawa school also is said to have been sacrificed in order to enhance the prestige of the religious doctrines in Mt. Koya. Whereas Tachikawa-ryu school was tied to the Southern Court, Yukai was tied to the Northern Court. Therefore it is said that the Tachikawa school was entangled in not only religious power but also in political power.
Besides these questions, some see the difference between remarks and behaviors by Ninkan and Monkan and the creed in the Tachikawa-ryu school, and doubt the relationship between them and the Tachikawa-ryu school.
However as almost all records are now lost, many questions still remain hidden and unclear. "Juhoyojinshu" and "Hokyosho" (Selections from the Precious Mirror) are the literatures which still survive today but they were written from a standpoint hostile to the Tachikawa-ryu school. Therefore it would probably be best to look on them as having the intention to slander the creed of the Tachikawa school.