Shingon 真言 is a school of esoteric Mahayana Buddhism founded in 9th-century Japan by Kūkai (Kōbō Daishi). The word itself is Japanese for mantra. Literally: "true word." And that captures the heart of this tradition — words, sounds and syllables that are not simply spoken. They carry a power. A power compressed over millennia of meditative practice.
Shingon is also the name of a Buddhist school in Japan — the Shingon-shū 真言宗. This school of esoteric Buddhism still preserves rituals, meditations and initiations that have been passed on for more than 1200 years. In an unbroken chain. From master to one who receives.
And it is from this tradition that the foundations of Reiki come.
Kūkai — the man who brought it all back 空海
The story of the Shingon school in Japan begins with one man: Kūkai 空海, born in 774, posthumously honoured as Kōbō Daishi 弘法大師. A monk who at age 31 sailed to China to receive the esoteric teaching directly at the source.
In China he met Master Huiguo, the seventh patriarch of the esoteric lineage. Huiguo recognised at once that Kūkai was the right successor. Within months he transmitted the entire system: the initiations, the mantras, the Siddham script, the Mandalas, the rituals. Everything.
When Kūkai returned to Japan in 806, he did not just bring texts. He brought a complete spiritual technology. Mantras that transform the mind. Mudras that turn the body into an instrument of meditation. Mandalas that make the invisible visible. And initiations that open the channel between practitioner and cosmic power.
In Shingon Buddhism there are three ways the practitioner connects to cosmic power: body (Mudra), speech (Mantra) and mind (meditation). When all three are activated at once, what arises is what Shingon calls Sanmitsu 三密 — the Three Mysteries. The same structure shows up in the Reiki practice.
What "esoteric" really means 密教
In the West, "esoteric" often sounds like secret knowledge that is deliberately hidden. In Japanese Buddhism, Mikkyō 密教 — the esoteric teaching — means something else. It is not about hiding anything from anyone. It is that certain experiences only open up through direct transmission. From master to one who receives. You cannot understand them from a book. You have to receive them.
That is why initiations are so central to Shingon Buddhism. An initiation — in Japanese Kanjō 灌頂 — is not a symbolic act. It is an energetic transmission. The master transmits a power that, from that moment on, the practitioner carries within and can deepen through practice.
Sound familiar? It should. The Reiki initiations work exactly the same way. That is no coincidence.
Kaji — merging with the power 加持
The central ritual form in Shingon Buddhism is called Kaji 加持. In this ritual the practitioner connects — through mantras, mudras and contemplative meditation — with a specific spiritual power. A Buddha. A Bodhisattva. A protective deity. It is not worship. It is merging.
In the Kaji ritual, Siddham script is used — sacred letters from Sanskrit that in Japan are understood as carriers of cosmic energy. Each Siddham character is sound, image and power at once. When the practitioner writes, recites and visualises the character in meditation, all three Mysteries are activated together.
In 834 Kūkai established a temple inside the imperial palace — the Shingon-in — to perform Kaji rituals there. That shows the weight the imperial court placed on this practice. It was not marginal. It was the spiritual foundation of the state.
The Great Sun Buddha 大日如来
At the centre of the Shingon tradition stands Dainichi Nyorai 大日如来 — the Great Sun Buddha. Literally: "the great, sun-radiant one, thus come." He is not a historical Buddha who once lived and died. He is the cosmic primordial power itself — the light that underlies everything that is.
In the Shingon understanding, Dainichi Nyorai is not somewhere out there. He is in everything. In every being, in every stone, in every breath. The practice is to experience that connection consciously — not intellectually, but in the body, in the sound, in the silence.
The two great Mandalas of the Shingon school — the Kongōkai Mandala 金剛界曼荼羅 and the Taizōkai Mandala 胎蔵界曼荼羅 — show the cosmic order with Dainichi Nyorai at the centre. They are not decorations. They are maps of consciousness.
From shamanic roots to Buddhist practice 修験道
Shingon does not stand alone. The tradition Reiki and Kuji Kiri come from has roots that reach far beyond Buddhism. They include shamanic Daoism, Shugendō 修験道, Shinto and esoteric Buddhism — traditions that have been woven together in Japan for centuries.
Before Buddhism arrived in Japan in the 6th century, there was already a deep shamanic tradition. The spiritual practice of Japan worked with spirit beings, forces of nature, and the connection between the visible and the invisible world. These older layers did not disappear when Buddhism came. They merged with it.
Shugendō — the "way of practice and direct experience" — is the clearest example. Mountain ascetics practised in the mountains of Japan. They wove Buddhist mantras together with shamanic rituals and developed a tradition that was neither purely Buddhist nor purely shamanic. Kūkai himself practised in the mountains as a young man, before he ever sailed to China.
Spiritual practice in the history of Japan 歴史
Buddhist practice has played a central role in Japanese society from the beginning. When Emperor Kimmei Tennō invited Buddhism to Japan in the 6th century, what arrived was not only Sūtras. With them came practices of divination, calendars and herbal medicine. Buddhist monks were the ones who spread the practice of energy work and mantra rituals throughout the country.
In the 8th century the Yōrō Code organised the different disciplines of spiritual and medical practice: acupuncture, moxibustion, massage, herbs — and explicitly rituals with mantras and meditations. Buddhist monks were exempt from shamanic practices, but not from the use of mantras for spiritual support. That is precisely the place where Shingon unfolded its power.
The connection to Reiki 靈氣
Mikao Usui was a Buddhist practitioner. The Reiki symbols he used come from the Siddham tradition. The initiations follow the pattern of Kanjō. The meditations work with the Three Mysteries — body, speech, mind. The life principles are written in the language of Buddhist Sūtras. All of this points to the Shingon tradition.
In Western Reiki this connection was forgotten over decades — or quietly simplified. The symbols were reduced to abstract signs, the initiations to simple rituals, the meditation to optional background. What was lost in the process was the depth.
Shingon Reiki restores this connection. Not as a museum reconstruction, but as a living practice. The symbols are understood and applied in their original meaning. The initiations follow the tradition of direct transmission. The meditation is not an extra — it is the foundation.
Reiki without its Shingon roots is like a tree without roots — it still stands, but it no longer grows. Those who know the tradition understand the symbols more deeply, feel the initiations more clearly, and experience meditation as what it was meant to be: an encounter with cosmic power.
Shingon today 現在
The Shingon school still exists in Japan today. On Kōyasan, the sacred mountain Kūkai founded in 816, more than 100 temples stand. Monks practise the same rituals there that Kūkai brought back from China 1200 years ago. It is one of the oldest unbroken spiritual traditions in the world.
Anyone who visits Kōyasan feels it immediately. The air between the cedars. The sound of bells in the early dawn. The stillness of the meditation halls. And above everything: the presence of something that cannot be put into words but communicates itself directly.
That experience — direct, embodied, beyond the intellect — is the heart of the Shingon tradition. And that is what Shingon Reiki carries forward: a practice that does not need to be explained, because it shows itself. In the moment you experience it.
Discover Shingon Reiki
Shingon Reiki weaves the living tradition of esoteric Buddhism back into the power of the Reiki initiations. Direct transmission. Authentic practice. A path that continues.
What is Shingon Reiki? What is Reiki?