Nao Kanzaki is a college student so naive that she blindly trusts anyone. But her naivety comes to a head when she unexpectedly receives a parcel containing 100 million yen. Unknowingly, she becomes part of the "Liar Game"—a dangerous tournament where winning requires betraying friends. If you win, you become rich, but if you lose, you'll spend your entire life paying off debts. When Nao finds no way out, she turns to a man who specializes in deceiving people. That day, Shinichi Akiyama, a former psychology student who is notorious for single-handedly sinking an entire company, is released from jail. Initially, Akiyama refuses, but seeing Nao's persistence and her plight, he agrees to help her. In a world full of lies and bribery, the two of them are forced to expose the true nature of those playing the game together.