When Helgar Ozaki was eight years old, he inherited unwanted black magic that fused with his soul. For years, he hid, trying to suppress his powers and avoid learning about them. However, he found himself in a relentless chase initiated by the soldiers of the Kingdom of Promesus.

His partner, Rio, vowed to keep him safe, failing every trial the military initiated against his childhood friend. But this arrangement also came to an end, and they were forced to take separate paths.

They were thrust into different situations, with new friends and journeys, sacrificing parts of themselves for what they believed would save the other. When they finally met, they found themselves embroiled in a conflict of interests, destinies, and emotions.