Shōtoku Taishi

Prince Shōtoku (574-22 February 622) is credited with the promulgation of the first constitution-like document in Japan. His real name is said to have been Umayadono. From an early age he displayed an uncanny intelligence, and there are stories claiming that at seven he had read a hundred sutras, or that he was able to listen to ten people at the same time and answer them in an accurate manner.

At 19 years he became regent for Empress Suiko. Being a devoted Buddhist, he worked to further spread Buddhism in Japan and founded the Hōryū-ji temple in 607.

Important political contributions

• in 603 he established the Twelve Level Cap and Rank System that encouraged personal merit and excellence, as opposed to the previous system of hereditary privileges 

Twelve Level Cap and Rank System table (Wikipedia)

•  in 604, he promulgated the Seventeen Article Constitution that laid down the virtues and moral foundation that were expected from government officials
• in 607, he sent an envoy to the Sui emperor of China and maintained diplomatic relations with the Chinese