Child Emperor, originally named Isamu, is a ten-year-old prodigy and the Hero Association's youngest professional hero. He holds the S-Class Rank 5 position primarily due to his exceptional intellect rather than physical strength. His appearance features light skin, short brown hair with a cowlick, large amber eyes, and a standard outfit of a light blue polo shirt, dark cobalt shorts, orange sneakers with white rims. He is frequently seen snacking on a pink lollipop and carries a signature black backpack housing his inventions. Personality-wise, he possesses a highly analytical mind, enabling calm observation and strategic planning in combat. Despite his maturity and willingness to collaborate, he resents being perceived as childish and becomes irritated when underestimated. He demonstrates genuine concern for others, prioritizing creating antidotes for allies and rescuing hostages. However, he exhibits overconfidence, occasionally dismissing those he deems inferior, and displays excessive caution, such as excluding potentially valuable allies due to mistrust or underestimating threats. His frustration with the uncooperative and prideful nature of fellow S-Class heroes and public figures like Sweet Mask contributes to his later disillusionment with the Hero Association. His physical abilities surpass normal humans, with enhanced strength exceeding some A-Class heroes like Stinger, reflexes capable of blocking Demon-level monster attacks, and durability allowing him to withstand significant impacts. His true power lies in his genius-level intellect and technological prowess as an expert scientist, inventor, and tactician. He creates advanced gadgets and formulates complex battle strategies. His inventions include analysis tools like Okame-chan and combat robots such as the Underdog Man series and the Dig Here Woof Woof No. 3 for scouting. His tactical mind incorporates contingency plans, like pre-placing components of his ultimate weapon, the Brave Giant mech suit, around potential battle sites. Notably, his cognitive abilities diminish when his blood sugar is low. The backpack utilizes compression technology, housing numerous devices beyond its apparent size. Key equipment includes spider-like limbs for mobility, utility tools like a chainsaw, shredder, and boxing glove, defensive items like the Invisible Wall film, and specialized weapons such as the Birdlime Shotgun and Tactical Pencil Case firing pencil missiles. His most formidable device is the Brave Giant, a prototype mech summoned from underground components. It operates for a strict limit of 2 minutes and 38 seconds and defeated the Dragon-level threat Phoenix Man by exploiting the monster's costume weakness. Other inventions include the Mini Octotank No. 8, Tickle-Tickle Bug 3, and the Enemy Machine Disabling Device Bug Basket-Kun. Following the Monster Association arc, significant development occurs. Disillusioned by the arrogance and lack of cooperation among adult S-Class heroes, he loses faith in the Hero Association and resigns to join the Neo Heroes, an organization more receptive to criticism. Concurrently, he changes his hero alias to Wild Emperor after learning the potentially embarrassing double meaning of his original Japanese name, "Dotei". Outside hero work, he attends elementary school but also serves as a teacher in afternoon sessions, sharing his knowledge. He maintains popularity among classmates, evidenced by receiving numerous invitations to social events. He operates a personal laboratory in Y-City for research and invention development.