Kaito Gōshō is the main protagonist of the Hero Bank anime, an elementary school student who finds himself at the center of the high-stakes world of Hero Battles. He is a hot-headed and determined boy, easily recognized by his signature regent hairstyle. His personality is often crude and prone to making all sorts of jokes, but beneath this exterior lies a strong-willed individual with a deep-seated eagerness to help others. This inherent desire to jump into action is what sets his entire journey into motion.

Kaito serves as the company president of the Gappori Company, a small enterprise he runs alongside his friends and classmates, which takes on various tasks to assist people. His life changes dramatically when, during a desperate Hero Battle against a stronger opponent, a mysterious priest named Sennen offers him a contract for a powerful hero suit known as Enter the Gold. With no time to consider the terms, Kaito hastily accepts the deal, using the suit's incredible power to secure a victory. However, the immediate triumph turns to shock when he learns that the rental fee for using Enter the Gold has saddled him with an enormous debt of ten billion yen. This crushing financial burden becomes Kaito's primary motivation, as he enters the world of competitive Hero Battles with the singular goal of winning enough money to pay off what he owes.

Despite the heavy pressure of his debt, Kaito's role in the story extends beyond simply chasing money. His love for Hero Battles themselves becomes a recurring theme, and his passion often inspires those he fights against to remember their own reasons for competing. He faces a wide variety of opponents, from corrupt authority figures to struggling friends, and his approach is consistently straightforward: he confronts problems head-on with determination and a refusal to back down, which frequently earns him the crucial support of spectators and turns the tide of a match.

Kaito's key relationships are central to the narrative. His closest companions are Nagare Amano, Mitsuo Zaizen, and Fukuta Kanemaru. Nagare, in particular, serves as both a close friend and a significant rival, who often feels inferior to Kaito's natural drive and eventually makes a dark contract of his own to gain power, setting them on a collision course. Mitsuo acts as the managing director of the Gappori Company, while Fukuta, who has a large build and ends his sentences with though, serves as its prophecy chief, aided by his pet mouse Platina who can predict the future. At home, Kaito lives with his older sister, Ai, who is often left exasperated by his financial recklessness but ultimately cares for him.

Throughout the series, Kaito demonstrates notable development. While he begins as a somewhat reckless boy who signs a contract without reading the fine print, he grows into a more responsible, though still enthusiastic, competitor. He learns to value his friends and their contributions, and his definition of winning expands beyond just monetary gain to include personal honor and enjoyment of the sport. Kaito's notable abilities are most prominently displayed through his use of his hero suit, Enter the Gold. While the specifics of his combat techniques are varied, his greatest asset is his incredible resilience and willpower. In battles where he is outmatched or his money gauge runs low, it is his determination to win that allows him to withstand powerful attacks and find an opening to land the final, decisive blow. His journey is one of a fortunate and unfortunate boy, using a combination of fighting spirit and high-tech rentals to battle his way out of an impossible debt.