Hokuto Shinken
Kenshiro is the youngest of four adopted sons trained by the previous "Hokuto Shinken" successor, Ryuken. As a child, he was sent to Japan, along with his future nemesis Raoh and Raoh's brother Toki, to escape from their homeland, the war-torn Land of Asura. Along with Raoh, Toki and a fourth student named Jagi, Kenshiro, the youngest of the four, was trained in the art of "Hokuto Shinken" and eventually named successor by Ryuken. After surviving the nuclear war, he tried to live in peace with his fiancée Yulia, until Jagi instigates Shin, a jealous rival from the Nanto Koshuken school, to challenge, then defeat Kenshiro. Shin then engraved the iconic seven scars on Kenshiro's chest by stabbing Kenshiro with his fingertips and left him for dead. Prior to this event, he was more forgiving of his enemies, as shown in a flashback of Jagi's failed assassination attempt against him, in which Kenshiro chooses to spare Jagi's life after defeating him. When Kenshiro later fights his old rivals in the present, particularly Shin, Jagi, and Raoh, they all remark on Kenshiro's acquired mercilessness.