Katsumi Orochi, adopted son of legendary karate master Doppo Orochi, emerged from a tragic childhood marked by the death of his circus lion-tamer father. Recognized for his latent talent, Doppo took him under his wing, rigorously training him in Shinshinkai Karate. Dubbed the “Lethal Weapon,” Katsumi ascended to a 3rd dan rank, cementing his reputation as a martial arts prodigy. Early arrogance defined his career until pivotal battles reshaped his worldview. His clash with Kaoru Hanayama in the Maximum Tournament exposed his vulnerabilities, spurring the creation of the Mach Punch—a supersonic strike taxing his body to its limits. Rivalry with Chinese Kempo expert Kaiou Retsu drove his evolution, culminating in a hard-fought rematch ending in mutual collapse. Confronting Pickle, a primal warrior, Katsumi unleashed the Hitless Blow—an upgraded Mach Punch that briefly staggered his foe but cost him an arm. This defeat instilled humility, refining his combat approach into a measured, analytical style. Later, surgeons grafted Retsu’s severed arm onto his body, a macabre enhancement he wielded with chilling efficiency. His dynamic with Doppo oscillated between filial loyalty and fierce competition, each striving to prove their karate’s supremacy while maintaining unspoken respect. Though raised by Doppo, Katsumi honored his biological parents, crediting their lineage for his physical prowess. Standing 186.5 cm with a chiseled physique, Katsumi’s appearance shifted through the years—hairstyle alterations, an arm lost and replaced. His techniques prioritized surgical precision: the Quadruple Median Line Strike disabled opponents by targeting meridians, while the Five Vital Points Consecutive Attacks delivered crippling speed. After leading the Shinshinkai Dojo post-Pickle, Katsumi balanced mentorship with relentless self-refinement. In later conflicts, such as against Shishimaru in *Baki-Dou II*, Retsu’s grafted arm amplified his power, paired with a seasoned strategic mind. Persistent injuries and adaptations underscored his resilience, solidifying his legacy as a tenacious force within martial arts.