Oraimono is a collective term for primary education text books that were compiled from the late Heian period to the early Meiji period, mainly in the form of letters.
They derived from boilerplates (shosoku-shu) which were a collection of correspondence from the late Heian period written by those who were engaged in literary work, such as nobles (A similar item called "Tokarissei," reportedly from China, is preserved in Todai-ji Temple Shoso-in Treasure Repository, but even this had been arranged from the Chinese original, showing that oraimono developed independently with an influence from China). In later years, some oraimono were composed of knowledge and customs necessary for each social status, such as samurai, merchants and farmers, while 'Jizukushi,' which were not in the form of correspondence, were compiled for calligraphy practice. Also, there were those that included elements of geography, history, and morals, meaning that various forms of oraimono were written.
In the Edo period, all kinds of oraimono were made for text books at terakoya (temple elementary school during the Edo period),
It is almost impossible to have a grasp of the total number of oraimono as, in particular, many terakoya teachers tried to write their own oraimono, but existing ones are said to number about 7,000 kinds.
The oldest existing oraimono, "Meigo Orai" (Meigo's Correspondence), is believed to have been written by FUJIWARA no Akihira, a scholar in the late Heian period who served as Monjo hakase (professor of literature) and Daigaku no kami (Director of the Bureau of Education) (This book is also called "Unshu Orai" or "Unshu Shosoku" and is comprised of 12 months' worth of example sentences which are related to events of the respective months). The books that are said to be from around this time are "Kozanjibon Koorai" (Kozan-ji Temple Correspondence), "Kiko Orai" (Kiko's Correspondence), "Tozan Orai" (also called "Higashiyama Orai"), "Kasen Orai" (also called "Izumi Orai"), etc.
"Junigetsu Orai" (Twelve Months Correspondence), which took the form of two letters per month describing the turning of the seasons as well as seasonal events, was composed in the Kamakura period and became a good example for oraimono that followed. Then, by the early Muromachi period, "Kirei Mondo," "Zohitsu Orai" (also called "Zappitsu Orai") and "Teikin Orai" (a collection of letters used for family education), which is considered to be the most important work of oraimono from the medieval time, were all written. As "Teikin Orai" covers and plainly explains the practical knowledge necessary for life in samurai society of the time, this text book served as a standard oraimono until the Edo period. Then came "Fujino Orai" with more narrative tone, and "Sekiso Orai," which took a style of assembling similar kinds of items. Oraimono by this period of history were mainly written by the educated classes, such as nobles and Buddhist priests, and therefore the oraimono before the Edo period are collectively called 'Koorai' (literally, old oraimono).
There are around 40 existing koorai, and they can be categorized in the following five groups.
The first group of koorai includes books with letters, which are in forms of practical use, collected without any particular purpose, such as "Meigo Orai."
The second group consists of those like "Junigetsu Orai," which have an assortment of example sentences for letters arranged according to the 12 months of the year.
The third group is composed of volumes with a list of phrases and simple sentences for letters, with "Zohitsu Orai" being a typical example.
The fourth group represented by "Teikin Orai" comprises books of words and knowledge in the style of letters, which aimed to spread necessary knowledge as well as the form of letters.
The fifth group, which has "Fujino Orai" as an example, includes titles with sentences not only from letters but also from other documents such as official papers.
In the Edo period, on top of the then existing oraimono such as "Teikin Orai," new oraimono were introduced with different purposes. For farming villages, elements of the farming calendar were included in "Inaka Orai" (A Letter on Farming Village) (also called "Densha Orai"), "Nogyo Orai" and "Hyakusho Orai" (A Guide to Farming), etc. while "A Guide to Commerce," "Toiya Orai" (also called "Tonya Orai"), "Gofuku Orai" and "Banshokaisen Orai" and so on were the typical oraimono for merchants living in cities. Oraimono with historical episodes which started with "Fujino Orai" are called 'buke orai' (literally, samurai orai) and later developed into the historical poetry style oraimono, after Ikku JUPPENSHA established the biography style oraimono. Furthermore, oraimono featuring geography, scenery, and produce of other regions were written to interest children, which include "Nihonkunizukushi," "Miyakomeisho Orai" (Correspondence on Sights in Miyako (present-day Kyoto)), "Naniwa Orai" (Letters On Sights of Naniwa (present-day Osaka)) and "Nakasendo Orai," and in the period of the Meiji Restoration, "Sekaifuzoku Orai" was composed.