A skilled assassin, an eastern princess, a giant axe-wielding warrior, and a fierce female fighter.

Five couples from around the world are summoned together by a mysterious being known only as "The Agent". The Agent tells them that they must fight to the death in a tournament called the Ark Arena.

Should they refuse, they will be killed. There is no escape.

Thus, each couple, without knowing where they are or why they must fight, is swept away into a battle for their lives.

The sole reward for the victors? The promise of eternal life...