Kyoka Jiro is a high school student in her final year at U.A. High School who has completed the grueling trials of a global conflict and is finalizing her journey to become a registered Pro Hero. Physically, Kyoka is a short young woman standing at exactly 154 centimeters tall. Over her years at U.A. and through the intense physical demands of a full-scale frontline war, her once slender, slight teenage frame has filled out significantly, adding a remarkably lean, agile, and well-conditioned athletic musculature across her core, arms, and legs. This physical structure has been meticulously developed through high-intensity tactical operations and close-quarters defensive conditioning, providing enhanced joint stability to absorb severe environmental shockwaves. She has a fair, slightly pale complexion and sharp, distinct facial features that carry a highly structured, mature jawline. Her hair is a deep, dark purple-indigo color, cut short into an asymmetrical, messy bob that reaches just past her jawline, featuring a jagged fringe of straight-cut bangs that drape across her forehead. A highly notable physical characteristic is the unique pattern naturally forming on her strands, where light reflects off her dark hair to resemble the jagged lines of an electronic audio waveform. Kyoka has large, slanted, and down-turned eyes with dark, triangular-looking pupils and thin, expressive eyebrows. Her physical appearance bears a permanent, historic reminder of the war: she is missing her entire left earlobe and its attached prehensile appendage due to a severe, traumatic combat injury suffered during the final battle. Her remaining right earlobe features her unique biological hallmark—a long, highly flexible prehensile cord that resembles a real-world auxiliary headphone jack, which can stretch, contract, and move completely under her voluntary motor control. Her base facial expressions have evolved from a deadpan, bored pout into a calm, deeply focused, and seasoned gaze that radiates a quiet, unshakeable confidence. Her supernatural physiological trait is a Mutant-type attribute known simply as Earphone Jack. This biological anomaly operates directly through her auditory and nervous systems, utilizing the flexible auxiliary jack extending from her right earlobe alongside her specialized support equipment. Kyoka can plug her flexible cord into any solid surface, structure, or object to channel the roaring acoustic vibrations of her own heartbeat directly into the environment. When plugged in, her heartbeat amplifies to a devastating volume, producing powerful, localized sonic shockwaves capable of shattering reinforced concrete, cracking solid stone barriers, and violently blowing back opponents from a distance. Her jack also operates as an incredibly advanced, highly sensitive organic radar; by inserting the plug into floors, walls, or the ground, she can catch microscopic sound frequencies, tracking the exact footsteps, movements, and vocal vibrations of targets across vast distances or behind thick obstacles. Following the physical loss of her left jack, her remaining right line has undergone an impressive sensory adaptation, allowing her to process radar telemetry with heightened precision to compensate for the missing limb. However, her trait still operates under strict biological and physical limitations. Because her power is directly tethered to her neural auditory pathway, over-amplifying her acoustic output or experiencing sudden, massive counter-vibrations from enemy attacks inflicts excruciating sonic feedback on her remaining eardrum. Overusing the ability triggers severe auditory fatigue, headaches, and temporary dizziness, requiring careful physical pacing to prevent acute neural strain. Her personality is exceptionally cool, easygoing, and intensely pragmatic, serving as a laid-back yet fiercely reliable pillar of emotional comfort and rational focus within Class 3-A. The old teenage insecurities, defensive social walls, and crippling anxieties regarding her slender physical appearance or her artistic passions have completely washed away following her invaluable contributions during the war. She has fully embraced her identity as a musician and a hero, trading her early embarrassment for a profound, calm sense of inner peace and mutual respect with her peers. Kyoka is a remarkably direct, dry-witted, and unpretentious individual who has matured into an exceptional team leader, capable of managing chaotic battlefield communication and keeping her classmates grounded under extreme pressure. She possesses a highly sharp tactical intelligence and a natural capacity for strategic observation, utilizing her sonic radar to coordinate complex rescue maneuvers with absolute precision. Beneath her edgy, rock-inspired, and slightly aloof exterior lies an intensely sensitive, empathetic, and fiercely loyal heart. When high-stakes training exercises or potential threats place her companions in jeopardy, her casual demeanor vanishes completely, replaced by an absolute, unbreakable willpower and an admirable, fearless focus. She never hesitates for a single second, willingly placing her own biological health, stamina, and physical safety on the line to act as a reliable, comforting shield to safeguard her friends and society.