Miyoshi no Tameyasu (三善為康)
MIYOSHI no Tameyasu (1049-August 29, 1139) was an aristocrat and Sando-ka (a professional of mathematics) who lived in the latter part of the Heian period. He had a wide knowledge-base and wrote many books such as "Choya gunsai" (Collected Official and Unofficial Writings) and "Kaichu-reki" and "Shochu-reki" both of which were the origin of "Nichureki" (a dictionary written in the Kamakura period).
He was from the Imizu clan who was Gozoku (local ruling family) in Imizu County, Ecchu Province. In 1067 he went up to Kyoto and learned mathematics under Tamenaga MIYOSHI. Later he was adopted as a son by Tamenaga and succeeded the Miyoshi clan. After that, he learned Kidendo (the study of history) at the same time and aimed to pass Shoshi (an examination held by Shikibu-sho for determining whether applicants are employable), but failed several times (Later, he severely criticized the education of Kidendo in Daigaku-ryo (Bureau of Education under the ritsuryo system) for being only a tool for promotion by playing with Chinese poetry in the ending poem of "Shoku-senzimon" (Chinese poetry written by Tameyasu). In 1100 he was assigned to Shonaiki (an official working at Nakatsukasa (Ministry of the Central Office)) in Shorokuinojo (Senior Sixth Rank, Upper Grade). In the era of the Emperor Horikawa, he was promoted to San hakase (Doctor of Numbers) and the head of shoryo (tombs). In 1116 he wrote "Choya gunsai". He believed that the predicted lunar eclipse which was forecasted to occur on December 18, 1117 would not occur, and his idea turned out to be true ("Denryaku" (Diary of FUJIWARA no Tadazane)). On February 3, 1129, when he was 81 years old, he was conferred Shogoinoge (Senior Fifth Rank, Lower Grade). In addition, in the same year when rekido (a professional dealing with calendars) insisted kaireki (changing of calendar) because it was not good to put a leap month on August, he insisted that the opinion of rekido had no reason with Ryusan (隆算) of Suiyodo (a type of astrology). In his later years he had a strong believing in Amitabha and in the Tensho era he wrote "Shui Ojo-den" which succeeded "Zoku honcho ojoden" (Sequel to the Accounts of Rebirth into the Pure Land) written by OE no Masafusa and consequently wrote "Zoku Shui Ojo-den" as one of the ways of kanjin (temple solicitation) for Kechien (making a connection with Buddha to rest spirit). He lived long until 91 years old and it is said that when he was dying he continued to pray for Amitabha to surely lead him to gokuraku jodo (the Pure Land (of Amida Buddha)) by kudoku (merit) of Buddhist invocation for a long time and became Ojo-nin (a person who achieved gokuraku ojo (peaceful death)) ("Honcho shinshu Ojo-den" (New collection of hagiographies of those born in the Pure Land)).
Although he could not have good official ranks, he wrote various books even in his later years. His representative works were such as "Choya gunsai" (28 volumes), "Kaichu-reki" (10 volumes), and "Shochu-reki" (four volumes). Although "Kaichu-reki" and "Shochu-reki" were scattered and ultimately lost, "Nichureki" which was edited based on these books in the Kamakura period remains. In addition, he wrote books for children's education such as "Shoku-senjimon" and "Domoshoin" (a dictionary of Chinese characters) and a mathematics book "Sangenkyushiho"(三元九紫法) in which area he was professional, but the latter was scattered and ultimately lost.
In addition, he is well known to have strongly believed in Kannon Bosatsu (Kannon Buddhisattva) from a young age and later Jodo (Pure Land) sect. He left many books on Buddhism such as "Buppo Kangenki" (仏法感験記), "The engi (origin) of the Rokuharamitsu-ji Temple," "The legend of Eizan Konpon Daishi," "Sezoku Ojo Ketsugi" (世俗往生決疑)(scattered and ultimately lost), and "Kongo-Hannyagenki"(金剛般若験記) (scattered and ultimately lost) as well as the above "Shui Ojo-den" and "Goshui Ojo-den."