Ryu Nakanishi, designated G-5 and codenamed the Horned Owl, commands as the primary pilot of the God Phoenix and later the Gatchaspartan across multiple missions. His maritime expertise originates from childhood in a small fishing village, where he rescued Dr. Nambu from a whirlpool at age 13 during a research expedition. This pivotal act secured his recruitment, leading Dr. Nambu to relocate him to Utoland City under the guise of managing a yacht harbor—a cover for submerging the God Phoenix. His family, including father Matsuzo and younger brother Seiji, stands among the rare living relatives of team members, with a mother mentioned briefly but unseen. The 1994 OVA reimagines his background as half-Japanese, half-Aboriginal Australian, raised near the Great Barrier Reef. Here, he trains in the Ocean Rescue Command program and emerges as the oldest teammate at 25. Visually, the original series depicts him as broad-shouldered with shoulder-length brown hair, clad in a green-and-yellow "5"-marked shirt, while the OVA redesigns him with a deep tan, dyed mohawk ponytail, and surfer-inspired casual wear. Concept art from the cancelled Imagi film experiments with his physique—oscillating between muscular, towering builds and slimmer frames—and evolves his Bird Style armor through green-and-gold motifs. Balancing a laid-back demeanor with fierce loyalty and occasional arrogance, Ryu initially approaches missions with indifference before embracing his role. His physical strength and empathy shine alongside a habit of napping during downtime, once resulting in a missed critical alert. Combat tactics leverage brute force, employing a harpoon gun, the adhesive-coated Gripper elastic rope, and the Owl Sickle—a kusarigama-like weapon. As a pilot, he masters advanced maneuvers, including underwater operations, and mentors teammates in handling the God Phoenix. Sequels introduce new mecha: the amphibious Horned Tank, later destroyed in conflict, and the bulldozer-shaped Gatcha Five, which integrates into the Gatchaspartan. Cameos in crossovers like *Yatterman* and *Time Bokan: Royal Revival* feature him in non-speaking roles or brief comedic exchanges. International adaptations rename him "Tiny Harper" in *Battle of the Planets*, ironically highlighting his stature. Core traits—loyalty, nautical skill, and the juxtaposition of rural roots against heroic stakes—remain consistent across iterations, while adaptations reinterpret his ethnicity, age, and aesthetics. Though absent from media like the unproduced Imagi film, his legacy endures as the team’s unwavering pilot and emotional cornerstone.