Once upon a time, gods and goddesses live among the mortals.

People worship them in exchange for a blessing or a favor. They built a temple or a shrine to make the divine being stay. And people went to a particular deity depending on their needs. But some gods and goddesses grew tired of how weak humans are. And most humans can no longer stand the difference between them and the immortals.

Soon, an agreement was made. The Departure of Deities states that all immortals must leave the human world. Meanwhile, the demigods and demigoddesses must choose which side to leave behind. If they decide to stay in the human world, they will live as a mortal and will lose their inherited powers after several years. Immortality, however, is possible for them if they decide to be with the deities in another realm. But avoiding conflict and gaining the respect of the gods and goddesses was never guaranteed.

When most deities immediately left the human world, people learned that they could stop worshiping them. They only pray for a deity to protect them whenever natural disasters occur. And often some prayers were answered. People then believe that their prayers are a way to summon a god or a goddess. However, once a deity leaves the human world, they are never allowed to come back.

The world has changed since then. Temples became business districts. The four kingdoms build their own empire. As conflicts arise, people rely on their kings. But no one suspects that there are still some immortals in the human world and among them was a forgotten god.