Kouryu, youngest of the Three Color Dragons, serves antagonist Klaus Daggats alongside siblings Kokuryu and Hakuryu as elite martial artists within Spiral Palace. Specializing in Chinese combat styles, the trio is deployed to obstruct protagonist Taito Masaki’s climb through Klaus’ tower.

When Klaus commands an ambush against Taito, Kouryu’s fierce dedication contrasts with Hakuryu’s hesitation, born of skepticism toward their leader’s goals. Kouryu’s rash intervention activates a fatal trap, killing Hakuryu and fracturing the brothers’ unity. Driven by grief, Kouryu and Kokuryu launch a vengeful assault against Taito, wielding synchronized martial techniques honed through years of training.

Though defeated, Kouryu survives the clash that claims Kokuryu’s life. Departing Spiral Palace, he vows to honor Hakuryu’s legacy by dedicating himself to martial mastery, forsaking further violence. His story concludes within the core series, with no expanded appearances documented.