After Nao Kanzaki receives a strange letter and a suitcase containing 100 million yen, she learns that she has been selected to participate in the LIAR GAME. Nao turns to a former con artist to survive the twisted game.

Touka Kuroitsu is a research assistant who belongs to the Monster Development Department of the evil organization Agastia. However, the enemy she has to fight right now isn't the heroes of justice, but her boss. So long justice exists, evil too, will exist. This is the story of those who fight secretly in the shadows of justice and evil's confrontation.