1. Sai On, or Cai Wen in Chinese, known as Gushi-chan Bunjaku, was a scholar-bureaucrat official of the Ryukyu Kingdom, serving as regent, instructor, and advisor to King Sho Kei.

1. Sai On, or Cai Wen in Chinese, known as Gushi-chan Bunjaku, was a scholar-bureaucrat official of the Ryukyu Kingdom, serving as regent, instructor, and advisor to King Sho Kei.
Sai On is renowned for the many reforms he initiated and oversaw, and is among the most famous figures in Okinawan history.
Sai On edited Chuzan Seifu, a rewrite of Chuzan Seikan by his father Sai Taku.
Sai On was born in Kumemura, the village within the major port city of Naha which served as the chief center of classical Chinese learning in Okinawa, and the source of the vast majority of the scholar-bureaucrats who were raised to serve in the administration of the kingdom.
Sai On's father had likewise been a scholar-bureaucrat of Kumemura, educated in the Confucian classics, and had served on several tribute missions to China.
Sai On's father wrote the Chuzan Seifu by rewriting the Chuzan Seikan in 1701.
Sai On edited Chuzan Seifu in 1724, and it is believed that this was to give the work a pro-Chinese point of view.
At the age of 27, Sai On traveled to Guangzhou in China, where he studied economics, geography, and political administration alongside the more traditional Chinese classics.
Sai On is particularly known for the forestry and soil conservation efforts undertaken under his guidance to combat these problems.
Sai On retired from his ministerial post in 1752, the year after Sho Kei's death, but remained influential until his own death at the age of 79 in 1761.