Ten years ago, an inscrutable and abnormal territory known as Hell's Gate appeared in Tokyo, altering the sky and wreaking havoc on the landscape. The heavenly bodies disappeared, replaced by false stars. During this time, people who possess various special abilities emerged. Kept secret from the masses, these individuals, known as Contractors, are able to murder in cold blood. Various nations and organizations around the world use Contractors as spies and assassins such as the Syndicate, MI6, Evening Primrose, etc.

Which side will join? Will you help Evening Primrose to let the masses officially know about the Contractor's existence? Or perhaps do you prefer keeping Contractors at bay and stop their movements as much as possible? Well, what are you waiting for? Join now!