Matarashin (also known as Matarishin) is the principal image of the Tendai Sect, specially in the Genshi Kimyodan (a secret ceremony of the Tendai sect), and is also regarded as a guardian deity of the Amida-kyo Sutra and nenbutsu (Buddhist invocation).
In the section 39, 'the story of Matarashin in Jogyo-do Hall' of the "Keiran shuyo shu" (a collection of oral transmissions in the Japanese Tendai Sect which contains four stories about Myoe), there is a description that Ennin, a priest of the Tendai Sect, learned Inzei Nenbutsu (Chanting of the Buddhist invocation with a prolonged voice) of the Mt. Wutai Shan in China (Tang), was inspired upon hearing Matarashin's voice from the air on a ship to go back to Japan, built the Jyogyo-do Hall on Mt. Hiei, performed kanjo (ceremonial transfer of a divided tutelary deity to a new location) and Jogyo-zanmai (absorption in walking around Amitabha, invocating his name and nenbutsu), and began believing in Amitabha.
However, the religious service of Matarashin was started by Eshin school and Danna school of the Tendai Sect from the end of the Heian period to the Kamakura period, and it is thought to have begun around the same period of the establishment of the Genshi Kimyo-dan (one of the kanjo (a ceremony to be the successor) of the Tendai Sect) of the Danna school.
This deity consisted of the two Doji ogres of Teireita and Nishita and the three deities which are regarded to symbolize the three kleshas that poison the heart of man and Bonno (earthly desires) of avarice, anger and stupidity and show that the living things' bodies of Bonno are the Myotai (妙体) of hongaku (original enlightenment) and Buddhism's highest form of existence.
Until the Edo period, it had been enshrined at the time of kanjo in the Tendai Sect. According to folklore, it is sometimes regarded as Fukutoku-shin (god who bring fortune and luck), syncretized with Daikokuten (Mahakala) and so on. According to other theories, the enshrined deity of the Ushi-matsuri (Ox Festival) of the Koryu-ji Temple was enshrined by kanjo (ceremonial transfer of a divided tutelary deity to a new location) of Genshin Sozu as a guardian deity, and the Yashashin of the To-ji Temple is also said to be the same deity as this Matarashin.
Generally the features of this main deity is designed by placing a hood made in Tang on the head and kariginu (informal clothes worn by Court nobles), having Tsuzumi (hand drum) in the left hand, and beating it by the right hand. And the two Doji ogres of Teireita and Nishita in the left and right sides of the main deity are designed to be a dancing figure with putting Kazaori Eboshi (a traditional black fold-back cap) on the head and having a bamboo leaf in the right hand and myoga ginger in the left hand. There is bamboo and myoga ginger on both sides of the chuson (the principal statue in a group of Buddhist statues) and clouds on top, among which North Dipper Seven Stars is drawn. This is called the mandala (Buddhist visual schema of the enlightened mind) of Matarashin.