Kōshō Shinogi is a karate fighter who appears in the Baki the Grappler series. He is the younger brother of Kureha Shinogi and an expert in a specialized form of karate known as himokiri karate, where attacks are delivered as slashing strikes rather than blunt impacts. His signature technique is called cord cutting, which involves using his hands to sever or disable the nerves of his opponent, rendering them unable to move or sense properly. Shinogi possesses an extensive knowledge of the human nervous system, allowing him to target vital points with precision.

Shinogi is driven by a deep-seated sense of inferiority toward his older brother. As children, Kureha frequently came to his rescue, which left Shinogi feeling overshadowed and determined to prove his own strength. This motivation led him to develop his dangerous nerve-cutting style as a way to stand on his own. He is a serious and focused fighter, often calculating and deliberate in his approach.

In the story, Shinogi first challenges Baki Hanma in the underground arena and is knocked out. Later, he participates in the Maximum Tournament, where his first opponent is his brother Kureha. Seeing Shinogi's resilience and growth, Kureha forfeits the match. In the next round, Shinogi faces Gouki Shibukawa. During this fight, he manages to break Shibukawa's artificial eye, but ultimately loses the match. Despite these defeats, his abilities are acknowledged as considerable among the fighters.

Key relationships include his brother Kureha, whose presence both inspires and burdens him, and his opponents Baki and Shibukawa, who challenge him to grow. His development is marked by a gradual move away from his initial resentment and a demonstration of personal resilience. Shinogi reappears in later arcs, maintaining his role as a capable martial artist who continues to refine his unique style.