Duet of the Blue Sky (Colored) summary: On the battlefield, a boy with crimson eyes meets an angel with sky-blue eyes. Despite their hearts recognizing each other, their memories escape them, vanished into the far-off heavens. As the world swirls around them, all eyes are transfixed on these two figures, who hold the power to choose between sin and salvation. A decision must be made, and they must determine which path to follow.