Ryuu entered the world bearing strikingly pale skin, a trait his tribe deemed cursed, prompting them to abandon him as an infant. An ape named Kitty rescued the child, raising him as her own. After Tyranno killed Kitty, Ryuu vowed vengeance against the beast and dedicated himself to finding his biological mother, Esta.

His quest unfolded against relentless discrimination; many tribes associated his pale skin with the feared historical Whiteskins, leading to repeated attempts on his life, from being fed to dinosaurs to attacks by hostile tribes. During his travels, Ryuu forged a vital alliance with siblings Ran, a skilled herbalist, and her younger brother Don. Together, they offered mutual protection against threats like Tyranno and human enemies such as Taka, who pursued Ryuu out of hatred for his ancestry.

Kiba, a former chieftain whose tribe Tyranno destroyed, became Ryuu's mentor and father figure. He trained Ryuu in combat and shared the goal of killing the dinosaur, having previously blinded it in one eye. Kiba's death during a clash with Tyranno only hardened Ryuu's resolve to end the creature's reign.

Ryuu's search culminated in reuniting with Esta, who had always believed her son lived. However, their reunion was shattered by Taka, who used Esta as bait to lure Ryuu into a final confrontation. The series concluded with Ryuu achieving his twin goals: slaying Tyranno and reconciling with Esta. He continued his journey alongside Esta, Ran, and Don, ready to face new challenges.

Physically marked by his pale skin and dark hair, Ryuu often wielded a blunt knife as his primary weapon. His relationships remained platonic in the original narrative, though some international adaptations suggested romantic possibilities with Ran.