Sazara rules the northern kingdom of Keraru on the planet Mozaika. He starts as a benevolent monarch, leading his domain with wisdom and righteousness. A drastic change occurs when an evil priest aligned with a demon king possesses him, fundamentally altering his behavior and motivations.

Under the possession's influence, Sazara abandons just rule for violent conquest across Mozaika. He initiates multiple wars, inflicting widespread suffering on the planet's diverse peoples. His reign turns tyrannical, brutally suppressing dissent. This shift culminates in his execution of the loyal warrior U-Dante, who questioned Sazara's judgment after the possession.

Sazara's conquests and tyranny catalyze the central conflict. U-Dante's execution drives the protagonist U-Taruma, U-Dante's son, to rebel. U-Taruma dedicates himself to raising an army against Sazara's rule and ending Mozaika's suffering. The possessed king's actions create the resistance, positioning him as the source of the world's instability and the narrative's driving conflict.