The term "Main Service" does not appear in the direct writings of Oyasama--the Mikagura-uta, The Songs for the Service, or the Ofudesaki, The Tip of the Writing Brush. However, the term is used widely today and appears once in the Osashizu, The Divine Directions, and numerous times in the writings of first-generation followers.
On June 18, 1874 (fifth day of fifth month, lunar calendar), Oyasama went to the Maegawa household with a number of followers to receive the kagura masks She had previously requested Kyosuke Maegawa, Her elder brother, to make. These were Tenrikyo's first kagura masks. In the diary of the Maegawa household, there is a reference under the entry for that day to the Main Service, saying "God's servants from the Nakayamas of Shoyashiki Village performed the Kagura Service in its regular form (Kagura Honzutome)" on the evening of the 18th. Although the exact location of the Jiba had yet to be identified and the Service performers for the musical instruments or the Kagura had not yet fully assembled at that time, the word "Honzutome" or Main Service was nevertheless used. We can presume this is an expression of the sentiment that, unlike the practices that had continued up until that point, the followers were finally about to put on the masks and conduct the Service before God the Parent in earnest exactly as Oyasama taught.
In Zoku Hitokoto-hanashi Vol. II, the second Shinbashira writes, "It seems that after the morning and evening services were instituted, the Kagura Service was referred to as the Main Service in contrast to the daily services." The morning and evening services are conducted sitting down without the masks, with a fewer number of instruments, and they are not followed by a complete performance of the Teodori, the Dance with Hand Movements. The morning and evening services came to be regarded as informal services for these reasons while the Kagura Service came to be called the "Main Service." However, as the second Shinbashira pointed out, the Kagura Service is completely different from the morning and evening services from a doctrinal point of view, meaning that there is no formal-informal relationship between the two (refer to "Service" [5.59]).
The seated service and Teodori are performed at monthly services of local churches and mission stations. These services are held geographically away from Jiba and its performers are not the so-called "Service performers" who have been appointed by Oyasama or the Shinbashira. Yet, these services cannot be said to be "informal services" in contrast with the Main Service. There was a time when the term "Main Service" was also used to refer to services held at local churches. However, services at local churches should never be confused with the Kagura Service that is conducted around the Kanrodai.
In the Mikagura-uta, we read:
Even in the mountains, here and there,
It can be said that this "Service of Tenri-O(-)" refers to the service performed at churches or followers' homes. Today, the word "Main Service" refers to the entire Service held within the Inner Sanctuary of Church Headquarters, namely, the Kagura Service that is conducted around the Kanrodai-Jiba and the Teodori that immediately follows.