Together with Fukuoka Takachika, he was the principal author of the Charter Oath.

As a san'yo (Imperial Advisor) he helped draft the Five Charter Oath, and initiated policies of centralization and modernization.

On 1 January 1946, Hirohito issued the Ningen-sengen, in which he quoted the Charter Oath of Emperor Meiji and declared that he was not an 'Ningen-sengen'.

The goals of the restored government were expressed by the new emperor in the Charter Oath.

As his first major act, the Meiji emperor promulgated the Charter Oath - five promises to the people of Japan to bring fundamental change to the political system.

Although the promises were general and vague, the Charter Oath became the foundational document that effectively set the government's course for the rest of the Meiji period (1868-1912).

He was largely responsible for the promulgation of the Five Charter Oath of 1868, and the subject abolition of the han system.

In April 1868, the Charter Oath was promulgated, in which Emperor Meiji set out the broad general outlines for Japan's development and modernization.

Implicit in the Charter Oath was an end to exclusive political rule by the bakufu and a move toward more democratic participation in government.

To implement the Charter Oath, a constitution in 1889 with eleven articles was drawn up.