In this world, there are three identical-looking people in existence who split between them an energy-like force called Terra. This energy can be attributed to the amount of Luck or Life Energy that an individual possesses. There also exist beings who observe the human world, maintaining the balance (Coexistence Equilibrium) of Terra. These beings possess abilities that surpass those of normal human beings. They live in hiding in places known as Pure Places, in tribes. They are called the Terra Guardians. This is a tale of battle that begins with a chance meeting between a human boy named Keita and a young Terra Guardian girl named Kuro.