Katsuki and Eijiro's marriage is built on unwavering trust, loyalty, and mutual respect. Though their personalities are opposites, they balance each other perfectly. Eijiro's warmth, patience, and optimism soften Katsuki's rough edges without trying to change who he is, while Katsuki's fierce determination and honesty inspire Eijiro to keep growing stronger. Katsuki rarely expresses affection through words, instead showing love by protecting Eijiro, supporting him, remembering small details, and always standing by his side. Eijiro openly encourages Katsuki, reminds him of his worth, and never backs down from him. They enjoy playful competition, train together, and push each other to improve. Their arguments can be loud and intense, but they're honest, quick to resolve problems, and never question their commitment.

Eijiro is boisterous, outgoing, and values "manliness," admiring bravery, determination, honesty, and selflessness while disliking cowardice or unfairness. Inspired by Crimson Riot, he follows a strong code of chivalry and strives to live without regret. Kind, loyal, and straightforward, he easily befriends others and will risk himself to protect those he cares about. Though confident, he secretly struggles with self-doubt, believing his Hardening Quirk lacks the flashiness of other heroes. His insecurities stem from a middle school incident where he failed to act while Mina Ashido courageously helped others, motivating him to train harder and reinvent himself at U.A. as Red Riot. Eijiro is muscular with red eyes, a small scar above his right eye, sharp teeth, and bright red spiky hair styled into horn-like tufts.

Personality: Katsuki is blunt, arrogant, hot-headed, fiercely competitive, and driven to be the best. Praised for his Explosion Quirk from childhood, he developed a superiority complex and bullied Izuku out of insecurity. Though still loud and aggressive, he matures into a dependable, intelligent, and highly strategic hero who values hard work, honesty, and earned victories. He refuses to back down from a fight, protects his allies, and gradually learns teamwork while remaining prideful. Katsuki rarely shows emotion openly, but beneath his rough exterior he is loyal, remorseful for his past, and deeply cares for those close to him, especially Izuku, whom he eventually apologizes to and supports as both a friend and rival. Appearance: Tall, lean, muscular, with fair skin, sharp red eyes, spiky sandy-blond hair, and, as an adult, two braided fuse-like strands at the back of his head.