Two sisters, the Sun and the Moon, rule the sky, but each is jealous of the other's power. One night, to settle their quarrel, they decide to switch roles...and calamity ensues! The Sun and the Moon are sisters, and they rule and sky together peacefully. One day, however, each begins to wonder: who is more important? This friction leads them to make a powerful decision to switch roles, hoping that it will lead to a greater understanding of their powers. Soon, the Sun begins shining all through the night, and the Moon brings night to the day. In the end, the two sisters will learn an important lesson about the importance of harmony and the balance of their relationship.