Naofumi Iwatani, the protagonist of The Rising of the Shield Hero, is a young university student who was summoned from modern Japan into a fantasy world to become one of the four Cardinal Heroes, wielding the Legendary Shield. His initial cheerful and open-minded nature is shattered shortly after his arrival when he is falsely accused of attempted sexual assault by Princess Malty S Melromarc, an act that robs him of his reputation, money, and dignity. This betrayal, compounded by religious prejudice and contempt from his fellow heroes, transforms him into a deeply cynical, distrustful, and pragmatic individual. He becomes reluctant to trust strangers, often demanding payment upfront or using slave crests to prevent deception, and he shows little hesitation in employing underhanded tactics for his party’s survival.

Naofumi’s role in the story is that of a defensive specialist and tactical commander, unable to directly attack but capable of absorbing materials into his Legendary Shield to unlock a vast array of forms, each offering different skills and passive boosts. He excels at support magic, healing, and buffing his allies, and his high defense makes him nearly impervious to most attacks, with immunity to many poisons. His most dangerous power is the Curse Series, awakened by his rage, which grants offensive abilities like black flames and the Iron Maiden skill at the cost of mental and physical strain. Over time, his fighting style relies on teamwork and strategy rather than raw power.

His deepest relationships are with Raphtalia, a demi-human slave he originally bought out of bitterness but eventually comes to cherish as a daughter, and Filo, a filolial bird he raises similarly. Raphtalia’s unwavering loyalty is the first crack in his emotional armor, and through her and Filo, he gradually learns to trust and care for others again. He also forms meaningful bonds with figures like the warrior L’arc Berg, who becomes a brotherly figure, and with Rishia and other allies who earn his respect. Despite his continued gruff exterior and tendency to play the villain for effect, Naofumi proves to be fiercely protective of his chosen family.

By the time of season four, Naofumi’s development has shifted his motivations from pure survival and vengeance to a desire to protect and build. He has become more willing to rely on others, seeking win-win outcomes rather than solely self-interest. The season sees him traveling to the isolationist kingdom of Q’ten Lo to protect Raphtalia from assassins who mistake her for a throne usurper, and stopping in Siltvelt, a nation founded by a past Shield Hero, where he is hailed as a divine figure among demi-humans. His newfound responsibilities include governing Lurolona Village, rebuilding it into a stronghold, and preparing his party to face the remaining Guardian Beasts and the Waves of Calamity. Throughout, Naofumi remains a pragmatic and resourceful leader, often pretending to be a villain while genuinely striving to live up to the expectations of those who have placed their faith in him, and he continues to act as a foster parent to Raphtalia and Filo, hoping to secure their future even if he eventually returns to his own world.