Keyaru, a healing mage, endures years of physical and psychological torture after being enslaved by the kingdom of Jioral. His healing magic, though seemingly weak, allows him to manipulate bodies, memories, and even time itself. After reaching his limit, Keyaru uses his abilities to rewind time by four years, retaining all his memories and knowledge. With this second chance, he seeks vengeance against those who wronged him, adopting the alias "Keyarga" to conceal his identity.

The narrative unfolds as Keyaru systematically targets his former tormentors, including Princess Flare Arlgrande Jioral, who subjected him to relentless abuse. He manipulates events and people to dismantle the kingdom’s corrupt hierarchy, often employing morally ambiguous methods. Along the way, he encounters and recruits allies, such as Setsuna, a wolf demi-human seeking revenge for her tribe’s massacre, and Freia, a brainwashed version of Princess Flare whose memories Keyaru alters to serve his agenda.

The story explores themes of revenge, power dynamics, and the consequences of unchecked cruelty. Keyaru’s actions blur the line between justice and retribution, as he inflicts suffering on his enemies comparable to what he endured. The series delves into the psychological toll of his experiences, portraying his transformation from a victim to a calculating avenger. The plot is driven by his strategic maneuvers, interspersed with battles, political intrigue, and the gradual unraveling of the kingdom’s dark secrets. The characters’ motivations and relationships are central to the narrative, with Keyaru’s interactions often reflecting the moral complexities of his quest.