An ordinary salaryman and avid anime and manga fan wakes up in an unfamiliar room to find his body completely changed. Looking in the mirror, he realizes he has reincarnated as Yugram, the Empire’s third prince and the strongest final boss from the fantasy novel The Holy Hero Iris, which had also been adapted into a game. In the original story, Yugram is a villain who commits countless atrocities before being killed by the protagonist, Princess Iris of the enemy kingdom. Determined to avoid this doomed fate, he defects to Iris’s kingdom, hoping to live a lazy, luxurious life in exile. He finally meets Iris, but the peaceful slow life he imagined never begins. Instead, he finds himself acting as Iris’s swordsmanship instructor and bodyguard, going on dates with her, and even becoming a father figure to a young assassin named Nana. Yugram’s innate Magic Core grants him an absolute defense known as the Magic Barrier, allowing him to overpower nearly any foe with casual ease. As his actions deviate from the original story’s script, he is repeatedly dragged into chaotic situations: dealing with a suspicious dark elf group, foiling an imperial plot to attack the kingdom’s capital, and having his true identity discovered by another princess, Ricoris. War with his home empire breaks out a year earlier than in the original timeline, forcing Yugram to use his foreknowledge of the novel to help the kingdom’s forces and protect those he has come to care for. Amidst the battles and conspiracies, his romantic relationship with Iris deepens, blending humorous misunderstandings and affectionate moments into an over‑powered love‑comedy about a final boss who switched sides.