Japanese ryu: school
Although the Tachikawa and their activities were soon outlawed (in the 13th century) by the Japanese authorities, the school continued covertly until at least 1689 - and according to John Stevens (Lust for Enlightenment) it is still active today; in disguise.
As reported by Robert van Gulik, Nin-kan taught that sexual union and
one's living body was a means for
directly obtaining Buddha-hood, and the Tachikawa even held
mass-meetings during which tantric rites were practiced.
Another patriarch of the Tachikawa-ryu was Mon-kan (1278-1357). During his long and arduous
search for enlightenment - so the story goes - he had the vison of a goddess who appeared to him and said:
You must learn to experience the Great Bliss, the union of a man and a woman.
Liberation can only be realized through the act of sexual love.
This sums up the central tenet of all Tachikawa teachings: Buddhahood (infinite compassion, wisdom and liberation) can be obtained through controlled, ritual sexuality between motivated and experienced partners. The Tachikawa adepts are convinced that the loss of self, of ego, which occurs during sexual play can lead toward enlightenment - and that the moment of orgasm (called here the Lion's Roar) is a moment of revelation.
Some of the terms used above are quite intriguing, and every reader of Tibetan texts has most certainly come across Great Bliss, Lion's Roar, or the concept that sexual activity can lead to revelation. But there is no direct, historical link between Tibetan Vajrayana and Japanese Shingon/Tachikawa teachings. What they do have in common is that they mixed local teachings with Buddhism AND with Tantra ... and then arrived both at similar conclusions:
But back to Japan. Most of the sacred texts of the Tachikawa were either destroyed, or are, like the Sutra of Sacred Bliss,
hidden away in monasteries,
securely sealed and marked with the century-old notice
ake-bekarazu; [van Gulik, 1974; p. 359], a note that reads in plain English as
Do Not Open!.
However, a few Japanese and other researchers have meanwhile unearthed and published various material about the Tachikawa-ryu, especially in the last 20 years, for us to get an idea of their sexual symbolism and practices.
Since internet searches for the name are made difficult by the fact that Tachikawa is a Japanese surname as well as that of a city, I've included here a small Tachikawa bibliography for those who like to know more than described in this and the related pages.