Shin (シン) is Kenshiro's first major adversary in Hokuto no Ken series. Shin represents the Star of Martyrdom (殉星, Junsei) and is the successor of the Nanto Koshu Ken (南斗孤鷲拳, "South Star Lone Eagle Fist") style.
Shin was initially Kenshiro's friend and rival, who secretly desired Kenshiro's fiance Yuria from afar, but knew Yuria's heart was for Kenshiro and gave up to pursue her. After some motivation from Jagi, Shin challenged Kenshiro, after destroying Ryuken's grave stone, and defeated him, engraving the seven scars on his chest afterwards; subsequently taking off with Yuria by force.
After his first fight with Kenshiro, Shin formed the "King's Army" consists of outlaws ranging from Nanto Seiken users to brutish thugs. His army conquered a city that Shin later named it "Southern Cross", where he ruled as an oppressive tyrant who often committed various atrocities in the name of Yuria, much to her distraught and frustration.