Tenbu (Celestial Beings) (天部)
Tenbu (deva in Sanskrit) means deities of Buddhism. The origin of most of them are deities of Brahmanism in ancient India and later on, they were introduced in Buddhism and became Goho Zenshin (good deities protecting dharma), guardian deities of Buddhism. Ten (deity of heavenly realm), Tenbu-shin (Tenbu deity).
Word Meaning of 'Tenbu'
While Tenbu is sometimes simply referred to as Ten, the world where Tenbu resides in is also translated as Ten (Buddhism) (devaloka) and these two are often confused in Chinese character using regions. Although the term of deva in Sanskrit means 'deity,' it was translated as 'Ten' in China and the Japanese language followed such translation.
The Chinese character of 'Bu,' which makes up the term of 'Tenbu' together with the Chinese character of 'Ten,' doesn't have a significant meaning other than 'division' or 'group.'
Therefore, simply referring to as 'Ten' ought to be enough for understanding but in Japanese, the term 'Tenbu zo' (image of Tenbu) has been traditionally used instead of 'Ten zo' (image of Ten). The term of deva is also translated as Tenjin (heavenly deities) or Tennin (heavenly beings), but in this case, the shades of meaning are different to a certain extent.
The Roots of Tenbu
Brahmanism deities in ancient India, the roots of deities of Tenbu, include a wide variety of deities ranging from the deity of universe creation to those of evil spirits or demons. These deities have various appearances and nature including male deities (Bishamonten (Vaisravana), Daikokuten (Mahakala), and so on), female deities (Kisshoten (Laksmi), Benzaiten (Sarasvati, Buddhist goddess of music, learning, eloquence, wealth, longevity, and protection from natural disasters), and so on), type of kishin (nobles) (Bonten (Brahma, a major Hindu deity thought to be responsible for creating the world)), type of tennyo (a heavenly maiden) (Kisshoten), type of rikishi (strong men) Kongo Rikishi (protector deities) and type of busho (Japanese military commander) (Juni Shinsho (the twelve protective deities)), and so on.
Buddha' in broad terms that are the target of worshipping and making sculptures in Buddhism are generally categorized into four groups, namely 'Nyorai-bu' (group of Tathagata), 'Bosatsu-bu' (group of Bodhisattva), 'Myoo-bu' (group of Acala, one of the Five Wisdom Kings) and 'Tenbu' (group of protesters of Buddhist laws). Nyorai' is equivalent to 'Buddha' and means 'those who have attained enlightment,' 'Bosatsu' means those who are engaged in ascetic training in pursuit of attaining enlightment and under Exoteric Buddhism, Myoo-bu is not included basically because it holds Jikkai (the Ten Realms) theory. On the other hand, Esoteric Buddhism holds Sanrinshin (the three wheel-embodiments) theory which asserts that Buddha has three figures of Jishorinjin (the embodiment of the wheel of own-nature), Shoborinjin (the embodiment of the wheel of the true Dhara) and Kyoryorinjin (the embodiment of the wheel of injunction) and according to this theory, 'Myoo' is considered as Kyoryorinjin, the incarnation of Nyorai, that forcibly guides people who cannot be educated by preaching only. Therefore, many Myoo sculptures have fierce facial expressions called hunnu. In contrast with deities belonging to the above three groups, those belonging to 'Tenbu' carry the connotation of a guardian deity of Buddhism or a deity of fortune and many of them are the target of worship seeking worldly divine help.
Deities Belonging to Tenbu
Principal deities belonging to Tenbu are Bonten, Taishakuten (Sakra devanam Indra), Shitenno (four guardian kings) that consists of Jikokuten (Dhrtarastra), Zochoten (Virudhaka), Komokuten (Virupaksa) and Tamonten (Vaisravana) (Bishamonten (Vaisravana)), Benzaiten, Daikokuten (Mahakala), Kisshoten, Idaten (Kitchen God, Protector of Monasteries & Monks) Marishiten (Goddess of Wealth & Warrior Class), Kangiten (Nandikesvara, Ganesh in the Buddhist pantheon), Kongorikishi, Kishimo-jin (Goddess of Children) (Kariteimo), Junishinsho, Juniten (twelve deities), Hachi Bushu (or Eight Legions, Protectors of Buddhist Teachings) and Nijuhachi Bushu (The twenty-eight attendants of Senju Kannon), and so on.
Shitenno, Hachi Bushu, Juniten, Junishinsho and Nijuhachi Bushu are known as the group of deities that aim to enhance the power of protecting Buddhism as guardian deities by gathering several deities.
These deities are enshrined in various places, for example at both sides of a temple's entrance gate, nearby Honzon (principal image of Buddha) or around Butsudan (Buddhist altar) but in the case of Bishamonten and Benzaiten, they are often enshrined as Honzon and are the target of worship.