Tachikawa-ryū

Tachikawa-ryu (立川流) is a Japanese school of esoteric Buddhism (Mikkyō) of Shingonshu founded in 1114 by the monk Ninkan (仁寛) (1057-1123 AD) in an attempt to create a Japanese tradition corresponding to Indian Tantra (Skt., Vamachara).

History

Tachikawa-ryu is a former branch of Shingon Mikkyo founded by the monk Ninkan. As such it is a school of esoteric Buddhism founded on the principal of using energy to control supernatural and cosmic forces and through these energetic rites and rituals attain enlightenment. Tachikawa-ryu is no different in its approach other than it chooses to focus on perhaps the most powerful form of energy - sexual energy thus belonging to left-hand tantra.

The school formed in the early 12th century, allegedly by combining Onmyodo (Taoism, Japanese esoteric cosmology) with Shingon ritual practices. It is so named because it was founded in the town of Tachikawa in Musashi Province, Japan. Ninkan is said to have transmitted the esoteric teachings of Shingon to a Taoist Onmyōji (civil servants belonging to the Bureau of Onmyō), who then combined the two methods into a single school. Because of its use of ritual sexual energy and accusations of involvement in so called “black” magic, the school was frowned upon by Orthodox Shingon leaders (who perform non-sexual right hand Tantra rituals), and its monks were frequently sent into exile. The monk Yūkai (1345–1416) is generally credited with taking the lead on extirpating the Tachikawa-ryu school from Shingon.

Since most Tachikawa-ryu texts were destroyed much of its history and teachings must be reconstructed. The institutes who do have Tachikawa-ryu texts and information pertaining to the school are generally unsympathetic and hostile towards Tachikawa-ryu ideologies and therefore refuse to lend any sort of help to the matter.(Sanford 1991)

What is known is that the school was founded in about 1113 by the Shingon monk Ninkan. Ninkan was an instrumental figure not only on the formation of Tachikawa-ryu but in Shingonshu as well. In about 1113, Ninkan was exiled from Koyasan to the province of Izu after getting caught on the wrong side of a political dispute. In Izu he met an Onmyoji master from "Musashi no Tachikawa (Tachikawa of Musashi Province)" named Kenren (見蓮 also 兼蓮). Together the two created the school of Tachikawa-ryu.(Sanford 1991)

Tachikawa-ryu must have been largely created within the few months Ninkan was exiled and committed suicide. Many historians believe he is mentioned simply as an apocryphal figure. Regardless, he would have had to draw on ideas already prevalent in Japanese society and within the orthodox branches of Shingon-shū(Shingon Buddhism) at the time, as there simply was not enough time for him to develop an entirely new branch and ideology before he died. Ninkan committed suicide less than a year later in 1114 by throwing himself off a cliff in protest, and it was left to Kenren to propagate the school.(Sanford 1991)

Tachikawa-ryu was, like Shingon, is based in vajrayana-tantra. Unlike its orthodox cousin it was much more inclined towards 'secret' left-hand tantra rituals with its usage of sexual energy as method to attain bliss. Ninkan primarily oited founder of Shingon, Kōbō Daishi (Kūkai 空海), text sokushin jōbutsu (即身成仏) (Bodily Buddhahood) to support his ideologies and views. This caused discontent in the orthodox followers.

It appears from the historical record that Tachikawa-ryu was very widely accepted and practiced and by the middle of the 13th century　during The Nanboku-chō period had become a major contender with the orthodox branch of Shingon. This marks what is considered the second period of the school. Beginning in the 13th century the orthodox branch of Shingon at Koyasan began a smear campaign against Tachikawa-ryu. This second period lasted until about 1500AD. The discrimination and attack by the orthodox branch at Koyasan reached its climax in about 1470AD.

From 1470-1500 marks the beginning of the third period, of the school. By this time the orthodox branch of Shingon had managed to formally denounce and excommunicate most teachings and practitioners of Tachikawa-ryu form its ranks. However, it was still very popular with the general populace. Tachikawa-ryu works were still published in works such as Sangi Isshin-ki (The Three Worlds Single Heart), Fudō-son Gushō (Humble Notes on the Immovable Lord), and Konkō-shō (Compendium of the Primal Cavity). Tachikawa-ryu ideas and influences also appeared in cultic practices with Dual Ganesha ( 双身歓喜天, Sōshin Kangiten) and Aizen Myō-Ō (Ragaraja), and in the other main orthodox school of mikkyo Tendai, in their extinct Genshi Kimyōdan cult. And also in the teachings and ideologies of Jodoshinshu(Pure Land Faith), especially the Himitsu Nembutsu (Secret Mystery of Mindfulness of Amida Buddha) developed by Kakuban and Dōhan. (Sanford 1991)

Theory and practice

The two main schools of Japanese Esoteric Buddhism (vajrayana-tantra, Japanese: mikkyo) are Shingon and Tendai. Tachikawa-ryu belonged to the first of these schools. It was injected into Shingon from Tibet via Taoism. First off, Tachikawa-ryu as a school of tantra is first and foremost a system of correspondences between microcosm (male) and macrocosm (female). Thus Tachikawa-ryu, as Shingon and Tendai, can be thought of as a reintegration of the world into the soteriological path, since man and world, man and the universe, are now fundamentally the same. In any case it is important to realize that sexuality is of an eminently cosmological and ritual nature. The union of male and female principals is seen as the source of all phenomena, expressed as the union of the godhead (male/Shiva) with his divinity or consort (female/Shakti) who represents the source of his power and wisdom. (White 2000)

In Tachikawa-ryu ritual sex is the primary hōben (skillful means) to enlightenment. Rites and rituals such as the famous Skull Ritual and the Horse Penis Ritual were initiations that involved the union of male (hōben – skillful/expedient means) with female (wisdom) to enact union with deity and sacred consort. These types of rituals aim to create and identify the practitioner with the deity/Emperor at the center of the mandala - which is the center of all tantric practice and theory.

The mandala is the tantric symbol of royal power, the seat of the Son of Heaven, the super position, the divine throne of High Jupiter. It is this notion that the king/emperor, standing at the center of his kingdom which he rules from the center mirrors the godhead’s heavenly celestial kingdom that the sex Rites and Rituals enacted by practitioners' of Tachikawa-ryu are aimed at creating. This royal ideology of “galactic polity”, the “exemplary center” comprising the king (male), his deity (female) and the capital (mandala), from which he rules, all united together as a single all encompassing force of divine high regality. Tachikawa-ryu practices, just as in orthodox Shingon, is aimed at enacting this esoteric union of macrocosmic (female) and microcosmic (male) and through their union create an idealized “utopia”, the idealized constructed kingdom of the Godhead (metacosm) with the practitioners as King and Gods, self-made gods, in this case Dainichi Nyorai (大日如来)(Vairocana) (also seen as Amaterasu) itself. (White, 2000)

Dakini-ten (荼枳尼天) was worshiped. In Shingon mikkyo, Dakini (荼枳尼) is an evil, also a malevolent spirit who is an associate of Enma-ten Yama (Hinduism) Yamarāja (यमराज) the god of death.

Sacred texts (tantras)

The primary literature for all schools of orthdox Shingonshu are the Mahavairocana Tantra, the Vajrasekhara Sutra, the Adhyardhaśatikā Prajñāpāramitā Sutra (Rishu-kyō), and the Susiddhikāra Sūtra (Soshitsuji-kyō 蘇悉地経). These are the four principle texts of Esoteric Buddhism. They are all Tantras, literally “treatise”, “exposition”.

These texts played a vital role in Tachikawa-ryu as well, obviously. But according to the author and Tachikawa-ryu historian, John Stevens as well as James Sanford, another, and perhaps the most important text to the ryūha (流派), was the Sutra of Secret Bliss (ca. 1100), the full title of which is Sutra Proclaiming the Secret Method Enabling a Man and a Woman to Experience the Bliss of Buddhahood in this Very Body. This sutra contains the school's general teachings concerning sexuality and its role in reaching enlightenment. It was Rishu-kyō.

Sutra of Secret Bliss

The text itself is a short tantra (exposition). It reads as follows:

"Sexual intercourse between a man and a woman is the supreme buddha activity. Sex is the source of intense pleasure, the root of creation, necessary for every living being, and a natural act of regeneration. To be united as a man and woman is to united with Buddha."

The sound A represents the Womb Realm (Garbhakosa-dhatu; Taizo-kai/胎蔵界), Mother (Yin/in), great compassion, and the red lotus. The sound UN [hūṃ] represents the Diamond Realm(vajra) (Vajradhatu); Kongo-kai/金剛界), father (yang/yo), wisdom, and the white stupa. A/Un (the alpha and omega) represents is female/male (non-duality, paradox), yin yang, ocean/mountain, mercy/charity, emptiness/form. The red seed from the female and the white seed from the male bring human beings into existence. The unity and integration of A/Un creates and sustains the universe. This is the truth, not falsehood.

Prior to performing these rites, the man and woman take these vows:

1) We trust in the teachings of the Tachikawa-ryu.
2) We vow to cooperate and come together in mutual accord in the body and mind at all times.
3) We vow to perform these rites carefully under strict supervision by a master of Tachikawa-ryu.
4) We vow to try not to argue or fight.
5) We vow to try and avoid competing, making unconstructive criticisms, or blame each other.
6) We vow to try not to over indulge in food or drink.

The Buddha couple should bathe together in a curative hot spring without physical contact. The couple must be in perfect accord in body, mind, and speech. The couple must be in bright, positive mood, free of gloom, despair, or unhappiness. The man is venerated as Fudo Myo-O (Acala)(不動明王); the woman is venerated and embodies Aizen myo-O (愛染明王)(Rāgarāja). The holy couple faces each other and they make the three prostrations (Sanrai　三礼). Reciting:

Male: "I aspire to enter the Womb Realm."

Female: "I aspire to receive the Diamond Realm (vajra)."

The room must be spotless and absolutely clean, well secluded, with a small altar. The secret Buddha image is kept veiled, not to be uncovered until after the rites are performed. Kuden　(口伝) (secret oral teaching), the instructions regarding the Buddha image are only to transmitted orally and never written down. Fresh flowers are placed on the altar, together with appropriate seasonal offerings from the mountains and the sea. Kindle fragrant incense. Light the room with five candles. (The candles are the five colors of the elements and are placed in the appropriate direction: fire-red, south; water-black, north; wood-green/blue, east; earth-yellow, south; void-white, west)

The Buddha image is one's own body. Therefore, the man and woman shed their robes in the corner (southwest) and face each other completely naked and adorned. The Rites are to begin at midnight. The man crosses his legs in the full lotus position and the woman sits on the top of the man and lets his jeweled jade stem enter her mysterious gate. (This posture reacts the position of many esoteric deities and their consorts, in particular that of Shiva and Shakti). During the sexual congress of the two roots of existence (A/Un), the breath should be harmonized in an A (inhale) and Un (exhale) rhythm. The man should keep his vajra pressed against the woman's womb as they meditate together, blending the male/female components of the five elements (Godai): earth, water, fire, wood, and air/void. If done properly, this blending of the elements will form a five-colored rainbow: yellow, blue, red, green, and white. The mother/father buddha posture is best, but other postures and mantra are allowed. (Goku-I Kuden Ari: secret oral instructions and essential teachings are given but unknown at this time)

However, at the break of dawn when the rooster crows, the Buddha couple should be in the mother/father posture. At that time, the Buddha couple should come to a mutual instant of universal bliss; that is the moment of universal truth, a state of pure ecstasy, an unobstructed integration of emptiness and form. This is the realm of Dainichi Nyorai (大日如来)(Vairocana), the Cosmic Buddha where myriad elements exist in perfect equilibrium."

Notes on the Sutra of Great Bliss

A 'a' is said to be present in each consonant, and to be the mother of all of the letters. If you open your mouth and breath out the sound is 'a'. In Sanskrit if you add 'a' as a prefix it makes a word have the opposite meaning: Vidya is knowledge; Avidyā is ignorance. So 'a' came to represent the essence of the Prajñāpāramitā, or Perfection of Wisdom, tradition. This idea was explicitly expressed in the Sutra of the Perfection of Wisdom in One Letter, that letter being 'a'. In Buddhism phenomena are said to neither absolutely exist, nor non-exist - they arise in dependence on conditions, and cease when those conditions cease. This is similar to a Hindu aphorism about reality which says: not this, not this. Conceptual categories such as existence and non-existence are not able to encompass the true nature of phenomena.

Un (hūṃ)- The various aspects take in all Truths, all teachings, all practices, and all attainments. It summarises the two basic false views of nihilism and eternalism, and shows them to be false. The Truth of things is that they are neither real nor unreal, these categories do not apply – this is a restatement of the Buddha’s fundamental insight into the nature of phenomena. See also Kukai's (Kōbō-Daishi) Ungi gi (meaning of the syllable hūṃ/hum).

The role of the man as Fudo Myo-O (不動明王) (Acala), and the woman as Aizen Myo-O Rāgarāja　is esoterically symbolic of the man and woman in unbreakable union and irrevocably stained with love/passion. Fudo myo-o is the general of the Five Wisdom Kings, his name means "Imovable one". Aizen Myo-O is also a Wisdom King, his name means, "One who is stained red with love/passion".

This sums up the central tenet of all Tachikawa-ryu 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 (unbiased objective understanding)- and that the moment of orgasm (called the Lion's Roar) is a moment of revelation.

Modern times

For all practical purposes Tachikawa-ryu is extinct. It was outlawed in the 13th century by the Japanese authorities, and almost all its writings were either burned, or sealed away at Koya-san and related monasteries. However, there have been claims that the school continued covertly until at least 1689 - and according to John Stevens (Lust for Enlightenment), it is still active today; in disguise.

The Tachikawa Skull Ritual

Among the many Rituals and Rites practiced by Tachikawa-ryu was the famous Skull Ritual. Rituals involving the use of human or animal skulls are not uncommon. The exact origins of the Tachikawa-ryu Skull Ritual are unknown, but it appears from historical texts to be similar in Ritual to Anuttarayoga tantras of Indo-Tibetan Vajrayana-tantra, in particular of particularly Hevajara Tantra and Candamaharosana Tantra. However, without further evidence no other conclusion as to its origin can be made.

The description of the Tachikawa-ryu Skull Ritual comes from the monk Shinjō. Little if anything is known about Shinjō except what he writes about himself. The Skull Ritual is detailed in one of his works titled Juhō Yōjinshū (受法用心集), written about 1270AD. (Sanford 1991) The ritual is described here as Shinjō describes it for the following reasons: this description is the best description of the Ritual, the Ritual itself is relatively unknown and shrouded in fallacy, and finally to preserve some record of the Tachikawa-ryu Skull Ritual for antiquity.

The Ritual is as follows:

If anyone would practice this secret Dharma (Ritual) and attain great Siddhi (magical powers), he must construct an object of worship (honzon). I do not refer to the auspicious face of a woman here; this Misogi (purification Rite) is a skull. There are, in fact, ten different types of skull that may be used:

1 the skull of a wise man
2 the skull of an ascetic
3 the skull of a king
4 the skull a shogun
5 the skull of a great minister
6 the skull of an elder
7 the skull of a father
8 the skull of a mother
9 a “Thousand Cranium” skull
10 a “Dharmadhātu” (entire material universal) skull.

The first eight are clear enough. The “Thousand Cranium” skull is made by grinding the tops of a thousand men’s skulls into flour and molding the bone-paste into a honzon. For the “Dharmadhātu” skull, one must go to a cemetery on the chōyō (an onmyodo festival held on the 9th day of the 9th month. Since the number 9 is the perfect maximum yang/yō in Chinese divination it is seen as a particularly powerful and auspicious day. See: kuji-in), collects a large number of skulls, chants Dākini represent an especially crucial component of the Skull Ritual) incantations/prayers, and prays over the skulls. Finally, he takes the one, that when placed at the bottom of pile of skulls repeatedly rises to the top of the pile; or else he goes out on a frosty morning and selects the one that on which no frost has formed. Or, best of all, he selects a skull that is completely free of suture lines.

Whatever type he chooses can be made into a Honzon (本尊) (object of worship). For any of the ten types of skull there are three methods of construction possible. These are “the whole head”, “the small head”, and “the moon-shaped head”. For “the whole head”, the officiant uses the original skull. To this he adds a chin, puts in a tongue and teeth, and covers the bone with a hard lacquer so that it looks just like the unblemished flesh of a living person. When the skull has been completely formed, he places it in a box. Then he must have sexual intercourse with the skull and with a beautiful and willing woman, and must repeatedly wipe the liquid product (the mixture of male and female seminal and vaginal secretions) of this act on the skull until it reaches 120 layers. Each night at midnight he must burn “Spirit returning” incense (frankincense/hangon-kō), pass the smoke through the eye holes of the skull, and chant a “spirit returning” mantra fully and perfectly one thousand times.

After carrying out the procedure above for a number of days, the officiant places the appropriate charms and secret talismans (sōō motsu) into the skull. Once this procedure has been meticulously completed, he covers the skull with three layers of gold and silver leaf. Over these layers, the mandala must be inscribed, and then more gold and silver leafe applied, then another mandala applied over that, just as before. Thus the layers of gold and silver foil and sacred writings are built up – the outer layers are five and six, then in the center thirteen layers, all over the base of 120 layers of the red and white elixir (male and female sexual secretions). (Presumably this will equal the thickness of muscle and flesh of a real person) The ink of the mandlas should also be the twin fluids of intercourse.

Cinnabar (mercury sulfide) is rubbed into the tongue and lips, the teeth are set in silver leaf, and the eyes are painted in comely fashion, or, precious gems (jade, mother of pearl, or cornelian) can be used for the eyes. Them face is painted white and rouge patted in to create the appearance of a beautiful woman or boy. The image must look prosperous and have a face that smiles without the slightest hint of reproach.

During the entire process the sacred skull is to be kept on an altar in a place where no one ever goes, and various delicacies, beautiful flowers, and fine wines are to be offered to it. No one must go there (to the skull altar) but the craftsman, the adept, and the woman. There (at the skull altar) they must happily and willingly and ceaselessly disport themselves as if celebrating the first three days of the New Year. Each act and word must be wholly free of any sign of care.

Once the Honzon is finished, it is installed on the altar. Offerings of rare things are made daily; spirit-returning incense is burned; and the various observations are carried out at the hours of the Rat, the Ox, and the Tiger (midnight to dawn). With the arrival of the Hour of the Hare (dawn), the Honzon is placed in a bag made of seven layers of brocade. Once this bag has been closed, it is not easy to reopen. Every night the bag is held close to the adept’s body to keep it (the skull) warm; during the day it is placed on the altar, where delicacies (fowl, fish, meats, blood, rice, and so on) must be gathered and offered for its nourishment.

For seven years, day and night, the adept must and will devote the whole of his being and mind to this practice. When the eight year comes, the ascetic will obtain siddhi (magical powers). For those who reach the highest grade of practice, the Honzon will return to life and speak aloud (presumably predicting the future and bestowing upon the practitioner great wisdom and knowledge). Since it will inform him of all events of the universe, he should listen carefully to it and thus become as someone with divine powers. For practitioners of the middle rank, the Honzon will tell them the meaning of their dreams. It will not speak to those of the lower ranks, but all their desires will come to be realized in accordance with their wishes.

The second method, the “Small Head” method, exists because of the difficulty of carrying around a whole head. The top of one whole skull can be divided into eight pieces　and each piece used as a face lacquered into a plate made of wood of a sacred tree. Again, one sketches in the mandala in thin layers, daubs the Honzon with the twin waters of intercourse, inserts the appropriate charms and talismans, and decorates the face just as before. The “Small head” is then hung around the neck but under the garments, and nourished just as before.

In the case of the third. “Moon-Shaped” method, a whole cranium is cut off at the eyebrows, the brain pan is carefully dried and cleaned, and the moon-shaped inner cavity coated with the lacquer of the twin waters of intercourse. Various charms and talismans are placed in it, again the mandala is laid out in thin color, all as before. On the surface of the “Moon-skull” the practitioner must paint a Honzon while continuously reciting mantras. Cinnabar in packed inside. Then the practitioner is to wrap the skull in a nine-layered monk’s habit made from silk stained with menstrual blood of a beautiful young virgin woman. He then places it in a nine-layered casket wrapped in seven layers of brocaded silk, hangs it from his neck under his garments (to keep it dry and warm), and devoutly recites mantras to it wherever he goes.

There are recommended variations on this procedure, from taking the skull to its final installation and resurrection, since several oral (Kuden) teachings have been handed down by the old and wise. I have noted and summarized only about one-hundredth of the whole Ritual. But in general this is how the practitioner carries out this Ritual.

Notes on the skull ritual

The attribution of religious and magical powers to skulls is almost a universal trait. Nonetheless, it is especially prominent in tantric Buddhism. For example, the practitioners of the proto-tantric Kāpālikas (Kapalikas) often carried a staff with a skull on the end of it believing it gave them sidhhi (magical powers).

The use of hango-ko (frankincense) to call up the dead may trace back to the folk tale of the ancient Emperor Wu of the Han dynasty. There is also an equally apposite tantric usage to be found in the Hevajra Tantra where it describes the “mudra” (seal) as a ritual partner in a sex Rite as a gril “possessed of frankincense and camphor”, a characterization that turns out to be an encrypted reference for blood and semen (red and white). Regardless, the religious and magical powers of female blood and male semen (the Twin Waters, or the Red and White) is standard in the more baroque forms of Tantraism. An example is found in the Yoni-Tantra (vagina Tantra) of the Kaulas that recommends that, “…the highest sadhaka (offciant) should mix in the water the effusion from yoni (vagina) and lingam (penis), and sipping this amrita (nectar), nourish himself with it.”

The idea of passing the smoke of incense through the eye holes of the skull is a reflection of the Buddhist belief that incense is pure until empowered by prayer or thought. Then once lit it is purified by the fire of Agni, and the pure distilled intention manifests as smoke which rises to the heavens. Thus by allowing the smoke to pass through the eyes (the eyes are the windows to the soul) the pure distilled intention is captured and condensed with the enclosed cranium of the skull.

Shinjō also provides notes in a short Q&A at the end.

1.

Q/ “Why is a skull used?”

A/ The bodies of living beings contain ten spiritual essences- three hun (kon – Jpn.) souls and seven p’o (haku – Jpn.). When a person dies, the three hun souls disperse and suffer rebirth in the Rokudō (six realms of transmigration), while the seven p’o souls linger about their old body as guardian spirits in this miserable world (人道/Nindo- realm of human form). The spirits that appear in ocular dreams are all manifestations of the seven p’o souls. When the practitioner takes a skull and carries out the Rite of carefully nourishing it, the seven p’o souls are happy to grant him the worldly fortune he seeks. If he draws the mandala and insets the secret charms, he will attain mastery of those occult powers appropriate to the mighty powers of the particular charms and mandalas used. This is why there are several types of installation ritual.”

2

Q/“Why are the twin fluids of intercourse used?”

A/”The vitality of living things has the twin fluids as its seed. When the skull is covered with these two fluids, the seven p’o souls that linger in the skull are revived. It is like adding water to a sprout seeds. Just so, the three hun and seven p’o souls of the human body were originally contained in the two fluids, which gradually congealed in the mother’s womb to become flesh and blood. The bodies of even noble men of wisdom are composed of hun and p’o souls in this way. In the present situation, the three hun souls of the twin fluids combine with the seven p’o souls of the skull, and a living Honzon (object of worship) is produced. Hun souls are called male souls, - o-tamashii, and p’o souls are called female souls, or me-tamashii, If yin/in and yang/yō are not in appropriate balance, a living body will not develop. If yin/in and yang/yō are in appropriate balance, a living body results.

After the skull has been prepared, the ascetic must diligently warm it against has bare skin, never letting it cool off, just like a bird warming her eggs to give them life. Taking care that the skull is warm and nourished for seven years is a secret (Mitsu –Jpn.) Ritual for the dākinī (dakini) who live in the Honzon. These dākinī are manifestations of Manjusuri (Monju) and of the Nāgakanyā, the serpent girl. Nāgakanyā is an earthly form of a dākinī-deva. She attained perfect enlightenment at the age of eighty years and the Honzon mirrors her example (Ritual she used to attain enlightenment)…

Further reading

• Fukuda, Ryosei. A Study of Materials belonging to the Tachikawa School, Part II : Index to the Konkusho.
• Manabe, Shunsho. Jakyö Tachikawa-ryö. Tokyo: Chikuma Shobö, 1999.
• Mizuhara, Gyoei. Jakyo Tachikawa-ryu no kenkyu (Tokyo, 1931: A Study of the Heterodox Tachikawa Sect). Kyoto: Toyama Shobu, 1968.
• Moriyama, S. Tachikawa Jakyo to sono Shakaitekina Haikei no Kenkyu. Tokyo: Shinkano-en, 1965.
• Utagawa, T. Shingon Tachikawa Ryu no Hiho. Tokyo: Tokuma Books, 1981.
• Kabanov, Alexander. The Basic Tenets of the Tachikawa-ryu and its Underground Rituals in Medieval Japan.
• Ruppert, Brian O. Pearl in the Shrine: A Genealogy of the Buddhist Jewel of the Japanese Sovereign. [Japanese Journal of Religious Studies 29:1-2, 2002]