Vajracharya in the context of "Chinese Esoteric Buddhism"

Vajrayāna (Sanskrit: वज्रयान, lit. 'Diamond Vehicle or Thunderbolt Vehicle'), otherwise known as Mantrayāna ("Mantra Vehicle"), Guhyamantrayāna ("Secret Mantra Vehicle"), Tantrayāna ("Tantra Vehicle"), Indo-Tibetan Buddhism, Tantric Buddhism, and Esoteric Buddhism, is a Mahāyāna Buddhist tradition that emphasizes esoteric practices and rituals aimed at rapid spiritual awakening. Emerging between the 5th and 7th centuries CE in medieval India, Vajrayāna Buddhism incorporates a range of techniques, including the use of mantras (sacred sounds), dhāraṇīs (mnemonic codes), mudrās (symbolic hand gestures), mandalās (spiritual diagrams), and the visualization of deities and Buddhas. These practices are designed to transform ordinary experiences into spiritual paths toward enlightenment and liberation, often by engaging with aspects of desire and aversion in a ritualized context.

A distinctive feature of Vajrayāna Buddhism is its emphasis on esoteric transmission, where teachings are passed directly from teacher (guru or vajrācārya) to student through initiation ceremonies. Tradition asserts that these teachings have been passed down through an unbroken lineage going back to the historical Buddha (c. the 5th century BCE), sometimes via other Buddhas or bodhisattvas (e.g., Vajrapani). This lineage-based transmission ensures the preservation of the purity and effectiveness of the teachings. Practitioners often engage in deity yoga, a meditative practice where one visualizes oneself as a deity embodying enlightened qualities to transform one's perception of reality. The tradition also acknowledges the role of feminine energy, venerating female Buddhas and ḍākiṇīs (spiritual beings), and sometimes incorporates practices that challenge conventional norms to transcend dualistic thinking.

In Vajrayāna Buddhism, an empowerment or consecration (Sanskrit: abhiṣeka, lit. ablution; sprinkling) is an esoteric initiation or transmission of secret teachings performed by a tantric guru (vajracharya) to a student in a ritual space containing the mandala of a Buddhist deity. The initiation is traditionally seen as transmitting a certain spiritual power (Sanskrit: adhiṣṭhāna, Tibetan: jinlap, sometimes translated as "blessings") which allows the tantric yogi to reach enlightenment swiftly or to attain other yogic accomplishments.

Many tantric practices are commonly said to be secret, and are only to be revealed after ritual initiation. Other tantric practices may be openly known, but are only considered to be effective after being initiated into the proper mandala which corresponds to a specific practice. The secrecy of teachings was often protected through the use of allusive, indirect, symbolic and metaphorical language (twilight language) which required interpretation and guidance from a teacher. The teachings may also be considered "self-secret", meaning that even if they were to be told directly to a person, that person would not necessarily understand the teachings without proper context or initiation. In this way, the teachings are "secret" to the minds of those who are not following the path with more than a simple sense of curiosity.

In Mahayana and Vajrayana Buddhism, the Five Tathāgatas (Skt: पञ्चतथागत, pañcatathāgata; (Ch: 十方佛, Wǔfāngfó) or Five Wisdom Tathāgatas (Ch: 十智如来, Wǔzhì Rúlái), are the five cardinal male and female Buddhas that are inseparable co-equals, although the male cardinal Buddhas are more often represented. Collectively, the male and female Buddhas are known as the Five Buddha Families (pañcabuddhakula). The five are also called the Five Great Buddhas, and the Five Jinas (Skt. for "conqueror" or "victor").

Shingon (真言宗, Shingon-shū; "True Word/Mantra School") is one of the major schools of Buddhism in Japan and one of the few surviving Vajrayana lineages in East Asian Buddhism. It is a form of Japanese Esoteric Buddhism and is sometimes called "Tōmitsu" (東密 lit. "Esoteric [Buddhism] of Tō-ji"). The word shingon is the Japanese reading of the Chinese word 真言 (zhēnyán), which is the translation of the Sanskrit word mantra.

The Zhenyan lineage was founded in China (c. 7th–8th centuries) by Indian vajrācāryas (esoteric masters) like Śubhakarasiṃha, Vajrabodhi and Amoghavajra. These esoteric teachings would later flourish in Japan under the auspices of a Buddhist monk named Kūkai (空海, 774–835), who traveled to Tang China and received these esoteric transmissions from a Chinese master named Huiguo (746–805). Kūkai established his tradition at Mount Kōya (in Wakayama Prefecture), which remains the central pilgrimage center of Shingon Buddhism.