Long ago, the realm of Burgund faced a demonic invasion led by the infamous 'Demon Lord', nearly succumbing to defeat at humanity's hands. However, salvation arrived in the form of the revered 'Heavenly Knight', who vanquished the malevolent ruler and restored tranquility. Such is the tale woven in the fabric of Burgund's history. Yet, concealed within the walls of Juvren Knight Academy lies a different reality. Here, Shun, a struggling student with a lineage entwined with the 'Heavenly Knight' and 'Demon Lord', contends with his formidable sisters harboring ominous ambitions and extraordinary abilities. As the siblings propel the world towards chaos and destruction, Shun vows to reclaim harmony within his fractured family. Determined to safeguard his cherished ones, the underachieving outcast embarks on a journey to carve his path as a hero amidst the looming shadows of conflict and peril.