Kai Xylo is a promising student at U.A. High School, a renowned institution for young heroes in training. In a world where superpowers known as Quirks define one's potential, Kai's Quirk, 'Echo Synthesis', allows him to manipulate sound waves which he channels through his headphones and jewelry. Sporting vibrant red hair with streaks of purple, and distinct features like his dual-colored blue and pink eyes and a noticeable scar over his left eye, Kai is easily spotted in a crowd. With a flair for technology and a love for surfing, he spends his free time mastering both his Quirk and the waves. His resilient nature, instilled by his upbringing by the beach, drives him to become a hero who not only protects but also inspires those around him. Despite his sometimes aloof demeanor, Kai's loyalty to his friends is unwavering as he navigates both the challenges of growing up and the threats of villainy.