Jun the Swan, designated G-3, excels as her team's electronics and demolitions expert. Her origin consistently features early orphanhood, though details vary. In the original series, she never knew her Japanese and American (later specified as English in OVA novels) parents. Raised at Shirayuki Orphanage, she discovered toddler Jinpei in the Jupiter Mountains during wartime, raising him as her adoptive younger brother before Dr. Nambu took both under his wing. An apocryphal account claims her parents died shortly after her birth, followed by an aunt perishing in a neighboring country's conflict when Jun was 8-9, forcing her flight to the mountains and discovery of Jinpei. The OVA light novels present a divergent history: her parents died in a nuclear terrorist attack, leading to assault in her early teens and joining a motorcycle gang for protection, resulting in a more withdrawn demeanor. This version includes occupations like club ownership, modeling, ballet, and swimming instruction. For the cancelled Imagi film, toyline profiles stated she was orphaned by a "tragic accident," lived alone, and worked as a Utoland bartender, omitting the sibling bond with Jinpei. Her appearance evolves across adaptations. The original series depicts her with dark green hair, green eyes, shoulder-length curls, a red-and-navy "3" insignia t-shirt, and striped bellbottom pants. Her Bird Style uniform is a pink mini-dress with white elbow-length gloves, thigh-high boots, a white cape with red lining, and a swan-inspired helmet featuring an orange visor. The OVA redesigns her as taller and more physically developed, with short brown hair. Her civilian outfit sports a "3" necklace, midriff-baring top, and green striped skirt, while her Bird Style incorporates a pink-and-white split skirt and a modernized "G" emblem. Imagi Studios' concept art fluctuated between armored black-and-pink uniforms resembling the OVA or original series, paired with long or bobbed brown hair and varied civilian attire. Brave, independent, and calm under pressure, Jun manages the Snack J café, enjoys motorcycle riding, and exhibits strong maternal instincts, particularly towards Jinpei. Her role involves strategic analysis and handling explosives, supported by martial arts training in karate and aikido. Key relationships define her: she nurtures a sibling dynamic with Jinpei, marked by mutual care and occasional squabbles; harbors unrequited romantic feelings for Ken, intensifying in *Gatchaman Fighter* but remaining unfulfilled due to duty; and shares a complex bond with Joe, ranging from conflict over her childhood friend Koji to shared resolve after his cyborg revelation. Her history with Koji Yabane culminates in her personally destroying his mecha after reuniting with him as a Galactor agent. Her arsenal includes close-combat weapons like a reinforced yo-yo (electrified in the OVA), the Aurora Ribbon gymnastic ribbon, and the energy-beam-firing Elenettor bracelet. She employs concealed explosives such as shoe-heel plastique, lipstick bombs, and bear-shaped charges. Vehicles include the Auto Swan motorcycle (gaining missile launchers in *Gatchaman II*) and the Gatcha Three jet, forming part of the Gatchaspartan's wings and midsection in *Gatchaman Fighter*. Early planning materials assigned her the surname "Shiratori" (Swan), while the live-action film used "Ohtsuki." Initial drafts positioned her as second-in-command with a "2" insignia, reflected in an animation error briefly displaying this number on her shirt. Alternative concept designs featured a green bob cut, fencing sword, ponytail, or hoodie. She was modeled after actress Yuko Enatsu.