The protagonist of Shamo. As a child, he was deemed a genius until one day he snapped and murdered his parents by stabbing them. Sent to juvenile prison, he learned karate to protect himself.
Ryou Narushima is consistently portrayed as unrepentant for the murder of his parents, repeatedly committing morally reprehensible crimes such as assault and rape. Although capable of redemption—as seen through his caretaking of his sister and various small charitable acts throughout the manga—Narushima ultimately embodies a Byronic hero descending into darkness, with his chances for reform gradually fading as he succumbs more and more to his depraved and brutal tendencies.
A recurring minor theme in the manga is society's moral stratification, how it condemns young criminals like Narushima, and how this condemnation pushes Narushima to the fringes of society, making his prospects for true reform and redemption even more distant.
Several supporting characters within Shamo serve as dramatic foils to Narushima, with Naoto Sugawara being the prime example. Famous, wealthy, and admired for the same abilities that make Narushima an outcast, Sugawara’s presence highlights society's cognitive dissonance towards violence. Narushima is despised for his violent traits, while Sugawara is celebrated and rewarded for using those same traits in a slightly different context.
Ryou Narushima is modeled after two individuals:
- For the juvenile delinquency aspect: "Youth A."
- For the martial arts aspect: Ryu Narushima (成島竜) of Kyokushin. This karate fighter shares the same pronunciation as the main character's name.
