While originally regarded as a wrathful deity obstructing rebirth in the pure land, and thus a "god of obstacles", with time he also came to be seen as a protector of adherents of Tendai doctrine, capable of warding off demons, especially tengu, as well as epidemics.

[6] Today it is assumed that Matarajin's name was derived from the terms mata and matara, Japanese transcriptions of Sanskrit mātṛkā.

[10] When the great teacher Jikaku (Ennin) returned from China to transmit the ritual for the extended vocalized nenbutsu, on his ship he heard a voice in the empty sky, which told him: “My name is Matarajin, and I am a god of obstacles (shōgejin).

[17] This term has been coined by Yamamoto Hiroko [ja] to refer to a variety of figures worshiped in medieval Japan who cannot be classified as either kami or buddhas and bodhisattvas.

[20] Faure has argued that the change reflected “the transition from a medieval Buddhist ideology still largely indebted to India to an early modern religiosity where the discourse of Mikkyō informs - and is gradually superseded by - other cultural forms, particularly the performing arts.”[21] Matarajin is primarily considered a "god of obstacles".

[25] This role is also highlighted in Matarajin ku (摩多羅神供) from Senmyō-ji, known from a copy prepared by a certain Ryōchō, where it is stated that he possesses “the numinous power of countering epidemic deities”.

[26] As a deity connected with epidemics, Matarajin is sometimes linked to oxen, similarly to Gozu Tennō and Susanoo (celebrated during the Ushinori matsuri, literally "festival of ox riding", in the Yasaka Shrine in Tennō-machi).

[31] The term shukujin could also refer to deities of outcast groups or settlements (shuku),[32] for example sarugaku actors and biwa hōshi.

[37] Information pertaining to this aspect of his character is known from documents from the Togakushi Shrine, first published in 2001, but originating in the eighteenth century, when it was managed by Buddhist clergy.

[39] As a result, in Tōshō-gū he is situated to the right of the main figure, Tōshō Daigongen (a form of Yakushi-nyorai), with Sannō Gongen [ja] placed to the left.

[1] A deity worshiped near the Eastern Pagoda on Mount Hiei, Ina Tenjin (移那天神), was historically identified as Matarajin and as a manifestation of Mahakala.

[8] According to the writings of the Tendai monk Kōshū (1276-1350), Matarajin was regarded as either identical with Mahakala or as one of the demonic dakinis accompanying him, and was believed to devour livers.

[43] This was considered to be a way to help those negatively impacted by heavy karma with reaching a pure land faster, similarly as in the case of analogous beliefs about other dakinis.

[45] A stone said to resemble a white fox located near the main hall of Enryaku-ji is referred to as Matara Tenjin in various documents, despite being associated with Dakiniten.

[50] Additionally, Jimon denki horoku, dated to the Muromachi period,[48] states that "Susanoo has many traces, among them Matarajin and Gozu Tennō in India, the god of Mount Song in China, and the great Silla deity (Shinra Taijin) in Japan".

[51] Sange yōryakki explains that "Susanoo, who is also called Matarajin" enabled Saichō to return safely from his journey to China because he prayed to this deity.

[58] In addition to the conflation of the two, in one of the reinterpretations of the cycle of myths focused on Susanoo, Matarajin and a horde of demons under his command assist him when he attacks Amaterasu.

[22] This idea might have initially developed because the latter was the central object of worship in the so-called "constantly walking samādhi", while the former was enshrined as the protector of the halls it was practiced in.

[65] According to Eison, the founder of the Shingon Ritsu, Matarajin had the face of Mañjuśrī; in later tradition influenced by his teachings the two deities could outright be identified with each other.

[11] Matarajin is commonly portrayed wearing an eboshi and kariginu (a type of robe worn in informal contexts), both of which were historically associated with Japanese aristocracy.

[30] Danzan Jinja, a contemporary Shinto shrine which replaced Tōnomine, a Tendai temple associated with the Fujiwara clan, is in possession of an okina mask kept in a box labeled as "Matara".

[37] However, William M. Bodiford has argued that little direct evidence exists for this assumption, and most primary sources instead state that Matarajin was enshrined to the left of images of Amida.

[26] According to the accounts of the monks Shukaku Hōshinō (1150-1202) and Gōhō (1306-1362), a protective figure of Matarajin was also housed in Tō-ji, at the time the main temple of the Shingon school.

[78] Matarajin was an important figure, following Kageyama Haruki's interpretation possibly even the honzon,[70] in Genshi Kimyōdan (元旨歸命壇),[76] a Tendai ritual which originated on Mount Hiei.

[13] Specifically, a song associated with Matarajin's two underlings, consisting of the alternating nonsensical phrases shishirishi ni shishiri alternating with sosoroso ni sosoro has historically been interpreted as allusion to sex organs or to sounds of pleasure, though this notion is based on only on texts presumed to be polemical, and finds no direct support in Genshi Kimyōdan itself.

[80] It was a part of a broader effort to reform Tendai, patterned on Siming Zhili's campaign of purifying Tiantai from perceived negative influence of Chan and Huayan traditions.

[79] By the 1720s, he became a deity obscure even for Tendai clergy, as evidenced by handwritten notes left on the margins of a number of known manuscripts, many of which highlight his absence from texts from outside Japan.

[29] The Shingon monk Tainin Myōryū, relying on Reikū Kōken's work, in 1782 declared him to be a "false icon created by the stupidest of stupid folks".

[80] The nativist scholar Amano Sadakage [ja], relying on the same source, condemned the worship of Matarajin as a "deviant" form of Buddhism.

[39] Due to his marginal importance in the nineteenth century, Matarajin was not targeted during the early Meiji shinbutsu bunri policies,[29] though for a few years the ox festival (ushi matsuri) dedicated to him in Kōryū-ji in Kyoto was not performed.