Fist of the Blue Sky (蒼天の拳, Sōten no Ken) is a manga series written and illustrated by Tetsuo Hara, with plot supervision by Buronson. It was serialized in Weekly Comic Bunch from 2001 to 2010, with the chapters collected into 22 tankōbon volumes by Shinchosha. It is a prequel to the popular 1980s manga Fist of the North Star, which Hara originally illustrated with Buronson writing. The manga was adapted into a 26-episode anime series that aired on TV Asahi from 2006 to 2007.
In the July 2017 issue of Comic Zenon, a continuation of the manga was announced titled Sōten no Ken: Re:Genesis (蒼天の拳 RE:GENESIS), which will begin serialization in their December 2017 issue.
The main protagonist of this story is Kasumi Kenshiro, better known as "Yan Wang" or "The King of Hell" (derived from the myth Yan Luo Wang). Kasumi is a laid back and chain-smoking Tokyo professor who is secretly the successor of the deadly Chinese assassin martial art Hokuto Shinken that travels to Shanghai, China after hearing that his Triad friend Pan Guang-Lin and Pan's sister Yu-Ling are in trouble.
In Shanghai, Kasumi fights the three Hokuto families, the Hokuto Sankaken (based on the royal families of Romance of the Three Kingdoms). At the same time he helps Pan's Qīng Bāng triad against their rivals, the immoral Hóng Huá Huì, in gaining territory and influence in Shanghai.