Tenya Ida hails from a distinguished hero lineage, his older brother Tensei having previously operated under the hero name Ingenium—a heritage that profoundly shapes his unwavering dedication to heroism and exacting personal standards. After attending Soumei Junior High School, he enrolls at U.A. High School and becomes Class 1-A representative. Physically, he possesses a tall, muscular build, short dark blue hair, and unique engine-like calves with exhaust pipes that manifest his Quirk. He wears glasses and adopts a helmeted hero costume optimized for air resistance, later modified by Mei Hatsume. A scar persists on his left shoulder from his confrontation with the Hero Killer Stain. By his final U.A. years, his damaged mufflers regenerate; post-graduation, he slicks back his hair, appearing taller and more muscular. His "Engine" Quirk grants superhuman speed via calf engines, featuring acceleration gears and techniques like "Recipro Burst"—a short speed boost causing temporary stall from overheating. Training unlocks "Recipro Extend" and later "Recipro Turbo," extending operation from 10 seconds to 10 minutes and achieving Mach 3 speeds. His combat relies on high-velocity kicks that crush metal. Academically, he ranks second in Class 1-A, demonstrating strategic prowess in missions. Disciplined and rule-bound, Tenya initially displays rigidity and formality from his elite upbringing, often employing chopping arm gestures and reprimanding peers for disorganization. Yet he deeply values friendship and protection, viewing his class role as a duty to safeguard others. His admiration for Tensei fuels ambition but breeds self-doubt and a tendency to idolize others while undervaluing himself. When Stain cripples Tensei, Tenya discards protocol for vengeance, nearly getting allies killed—a pivotal failure teaching him emotional recklessness's dangers. He retains a hand scar as a reminder, evolving to prioritize collective heroism over personal honor. Tenya grows emotionally open, initially concealing distress about Tensei’s injury and dismissing Izuku Midoriya’s concern. Post-Stain, he tearfully apologizes, revealing newfound humility. He later supports Izuku’s emotional struggles and advocates for Yuga Aoyama’s redemption after betrayal. His rigidity softens when joining unsanctioned missions to rescue Katsuki Bakugo and aid allies during the Paranormal Liberation War, accepting that heroism sometimes requires rule-breaking. Despite grudges (e.g., against Mei Hatsume for Sports Festival exploitation), he consistently prioritizes others' safety, physically stopping Izuku from reckless rescues. In later conflicts, Tenya stalls a Near High-End Nomu alongside top heroes during the Paranormal Liberation War. He helps retrieve an isolated Izuku and transports Shoto Todoroki to confront Dabi at Gunga Mountain, pushing his Quirk to its limits. Post-graduation, he inherits the Ingenium name, ranks as the No. 13 hero, and leads Team Idaten—his brother’s former agency—forging a legacy balancing family honor with hard-earned wisdom.