A race different from humans that lives on the Earth, called by the name "Another".
They usually live among humans, with the appearance of normal humans so most people don't know about them, but they are all over the world. They exists in many countries, and in Korea they appear as 'Dokkaebi' (type of spirit formed from inanimate objects, mentioned in Korean folklore) and ghosts.
Ordinary humans can't see their appearance until they reveal it on purpose. However there are people with special powers, and some of those powers allows them to see the real appearance of "Another".
Most Anothers have enhanced strength and speed than normal humans. They can also shapeshift. They also grow stronger by absorbing others' abilities.
Anothers are classified according to their power level.
- Battle types
- Highly-dangerous types
Strong Anothers are constantly hunting others of their kin in order to absorb their power. Many Anothers organization exists with most of them sharing world domination as common goal.