Is “Let his hair down and feigned madness to become a slave, and answered the Hongfan” true?
attested in history
According to the Records of the Grand Historian, Chapter on the Hereditary House of Song and Weizi, he admonished King Zhou of Shang but was ignored, so he let his hair down, feigned madness, and became a slave. When King Wu of Zhou visited him to seek advice on governance, he responded with the Hongfan.
Jizi
In official history, he is a virtuous royal clansman who served as Grand Tutor of the Shang Dynasty and was enslaved for remonstrating; in fiction, he is often portrayed as a loyal elder deeply concerned about his country and people.