Yeon Hajun hails from a leading Korean financial dynasty. His parents branded him an "unneeded child" after his brother Dongha's birth, inflicting deep wounds reflected in trauma markers like "Brand of an unwanted child" and "Hiding wounds behind the mask of a smile." Exiled to Japan at 13, he forged independence away from familial influence. During his Tokyo years, pivotal bonds formed: meeting Allen Sugasano at 15 and Anne Faulkner at 17 catalyzed the musical unit BAE. Despite Hajun’s icy exterior, these friendships became lifelines, helping him embrace his existence. He credits Allen and Anne as irreplaceable, vowing to pursue shared ambitions while demonstrating care through daily meal preparations for them. Standing 185 cm with a slender frame, Hajun possesses fair skin, blonde hair parted left, and striking pink eyes. His edgy aesthetic includes six left-ear piercings, three right-ear piercings, and a triple-line neck tattoo. He accessorizes with pink-tinted glasses, multiple rings, and the Feather Ring—his right-middle-finger Phantometal that conjures illusions when kissed. His style merges sophistication with streetwear: layered jackets, belts, and accent-colored sneakers (red/blue/white), complemented by coordinated BAE-branded stage outfits. Personality reveals stark duality. Publicly, he plays the "Smiling Aristocrat"—polite yet cruelly sadistic, masking solitude inherited from childhood trauma and familial scheming. Privately, resentment toward his parents fuels revenge vows. Though arrogance shields him, he softens around BAE. Worldly wisdom from his upbringing coexists with insect aversion and susceptibility to teasing. He juggles modeling, international studies, and Phantom Live battles as MC "48," wielding illusion-based Phantometal performances. His military-precise routine balances academics, photoshoots, gym sessions, skincare, and reading. BAE’s music champions self-determined fates, mirroring Hajun’s journey. During the "Road to Legend" tournament against Dongha’s group AMPRULE, Hajun dismissed their efforts as juvenile but acknowledged his brother’s autonomy, hinting at latent protectiveness beneath criticism. His evolution prioritizes collective bonds over solitary vengeance. While familial grudges linger, BAE fostered acceptance of his life and others’ significance—expressed through his commitment to "aim for the heights" with Allen and Anne. Daily essentials include a PC, lip balm, hand cream, and earphones. He favors organic food, tranquil park mornings, and study sessions, cites height as a charm point, and keeps future dreams secret. Tensions with Dongha simmer with mutual contempt, exacerbated by their father’s comparisons and regret over severing Hajun. Both brothers internalized paternal pressure to "dominate the lower ranks and reign at the top," fueling their musical rivalry.