Twenty years ago, nine heroes, including Korea’s Han Seojin and Lee Mirae, defeated the Monarch of Oblivion, who sought to erase humanity. Though the heroes claimed victory, the Monarch's final words warned of future doom. They established the World Hero School Competition to train defenders against the forsaken truth.

Years later, their son, Han Jiwoo, lives in Seoul, unaware of his parents' past. During his Awakening, he unveils a rare Dual-Class ability: Combat and Unknown, the latter linked to the Monarch of Oblivion. Sent to Eclipse Academy, Jiwoo becomes the center of attention amid admiration and doubt. A critical duel finally triggers his second power, awakening a voice within him tied to the Monarch, forcing Jiwoo to learn to control his extraordinary abilities while navigating the challenges ahead.