"SEVEN KNIGHTS REVOLUTION: Hero Successor" is a fantasy anime series set in a world where legendary heroes known as the Seven Knights once saved humanity from destruction. These heroes wielded powerful weapons called Eclipse, which granted them immense strength. However, after their victory, the Eclipse vanished, and the Seven Knights disappeared into legend. Years later, a new generation of warriors emerges, inheriting the legacy of the Seven Knights and their Eclipse weapons.

The protagonist, Nemo, is a young man who dreams of becoming a hero despite his lack of combat skills. His life changes when he encounters a mysterious girl named Faria, who possesses an Eclipse weapon. Faria is pursued by a powerful organization seeking to control the Eclipse for their own purposes. During a confrontation, Nemo unexpectedly awakens his own Eclipse, a weapon tied to the legacy of the Seven Knights. This event draws him into a conflict involving rival factions, ancient secrets, and the true nature of the Eclipse.

As Nemo trains to master his newfound power, he joins the Hero Academy, an institution dedicated to nurturing those who wield Eclipse weapons. There, he meets other successors, including Jill, a skilled and determined warrior, and Yuri, a calm and analytical fighter. Together, they face challenges that test their abilities and resolve, uncovering the truth about the Seven Knights and the Eclipse. The series explores themes of legacy, identity, and the burden of power, as Nemo and his peers grapple with their roles as successors to the legendary heroes.

The plot unfolds through a mix of action, intrigue, and character development, with battles against both human adversaries and monstrous creatures known as Shadows. The Eclipse weapons, each with unique abilities, play a central role in the narrative, as their origins and true purpose are gradually revealed. The story also delves into the motivations of the antagonists, who seek to exploit the Eclipse for their own ambitions, leading to escalating conflicts that threaten the world.

Throughout the series, Nemo grows from an inexperienced dreamer into a capable leader, driven by his desire to protect others and honor the legacy of the Seven Knights. The relationships between the characters evolve, with alliances forming and rivalries emerging as they confront their shared destiny. The narrative builds toward a climactic confrontation that ties together the threads of the story, revealing the ultimate fate of the Seven Knights and the Eclipse.