On the last day of school just before summer vacation, a strange letter arrived for high school student Aito Eyama, in despair for being unfairly bullied everyday. It was an invitation to a "prison game" where anyone could confine anyone they want for a month. During that month, the Player is allowed to do anything other than kill their Partner, and if the Player's name isn't revealed, the Players can get a large sum of money. (Source: Coolmic)

Humans are always evolving. The ones who evolved in the right path would embody superpower, and called the "White." However, the when their psyche can't keep up with the evolution of their body, they'll lose their mind and go berserk. They are called the "Black." Jin is a part of Black Line, the security company against the Black. He swears to eliminate all the "Black" from this world—whether by finding a cure to end the spread of the "Black," or with his own fist and power.