Year XX. Oukagai, located somewhere in Japan. It is what one would call a Chinatown.

In Oukagai, there are monsters known as Youma. Youma look like shadows with blurred outlines and vary in size. The stronger ones are capable of using sorcery.

Those who defeat Youma are called Youma Hunters.

There are humans who can use spiritual power, but their numbers are extremely small. These individuals must belong to an organization called the Yourankai. They hold regular meetings to ensure the safety of Oukagai.

Yourankai

The top of Oukagai. The government. None can defy them.

Seiryukai

Famous within Oukagai for solving problems with particular violence. Because of this, they receive few requests and operate out of a small office in a back alley. There is only one member.

Korouin

An organization with significant influence in Oukagai. They have many members, and the townspeople often rely on them.

There are only four descendants of the Four Gods.
If the Azure Dragon vanishes, the seas will rage.
If the Vermilion Bird vanishes, the sun will disappear from the earth.
If the White Tiger vanishes, the weather will turn violent with lightning.
If the Black Tortoise vanishes, the earth will wither.

However, the modern descendants of the Four Gods do not cooperate; they view each other as enemies.