Ryu Nakanishi, designated G-5 and codenamed the Horned Owl, hails from a fishing village. The 17-year-old son of fisherman Matsuzo Nakanishi and brother to Seiji, his backstory includes assisting Dr. Nambu during research at age 13, rescuing him from a whirlpool. This event triggered his relocation to Utoland City and eventual Science Ninja Team recruitment, leveraging his maritime expertise. His civilian role involves managing a yacht harbor, secretly housing the submerged God Phoenix. Low customer traffic allows frequent naps during downtime. Physical appearance differs across adaptations. The original series depicts him as heavily built and somewhat overweight, though primarily muscular, resembling a sumo wrestler. He stands 170 cm tall, weighs 80 kg, and has shoulder-length brown hair. His typical civilian attire is a green-and-yellow "5"-insignia t-shirt with khaki pants. His brown Bird Style uniform features a green cape with deep red trim, a green helmet bearing yellow eye markings, an orange beak piece, and a lavender visor. The 1994 OVA reimagines him as a 25-year-old, making him the team's oldest member. This version presents him as half-Japanese, half-Aboriginal Australian, with a childhood near the Great Barrier Reef and ocean rescue training. His design includes deeply tanned skin and a distinctive purple-and-blond mohawk ponytail. Civilian clothing adopts a surfer aesthetic, though he retains a "5" necklace. His OVA Bird Style shifts to deep green with gold accents. Personality-wise, he exhibits a laid-back, empathetic, and optimistic nature, often counterbalancing more intense teammates. He shows initial reluctance towards missions, preferring to stay at the harbor unless directly ordered by Dr. Nambu. Despite occasional complaints about limited combat roles, he maintains unwavering team loyalty. Prone to napping during boredom, he once missed a Galactor attack alert. Though generally easygoing, he can display arrogance and a violent temper when provoked. As the team's primary pilot, his maritime background enables expert maneuvering of the God Phoenix, New God Phoenix, and Gatchaspartan across aerial, aquatic, and space environments. His combat style emphasizes brute strength, grappling enemy vessels or body-slamming opponents. While preferring physical confrontations, he employs specialized weapons evolving across series: an original harpoon gun, an adhesive Gripper rope in *Gatchaman II*, and an Owl Sickle (a weighted kusarigama) in *Gatchaman Fighter*. His personal mecha progresses from the amphibious Horned Tank in *Gatchaman II* to the bulldozer-inspired Gatcha Five in *Gatchaman Fighter*, which forms the Gatchaspartan's rear components. International adaptations modify his name and characterization: *Battle of the Planets* calls him Tiny Harper, *G-Force: Guardians of Space* uses Hooty or Hoot Owl, and *Eagle Riders* names him Ollie Keeawani. These versions typically downplay or omit his family connections and maritime background, focusing on his piloting role within restructured narratives. Spin-off media offers no significant character development beyond brief cameos, such as non-speaking crowd appearances in *Yatterman* (2008) using his original design.