An uncommonly naive college student named Nao Kanzaki receives a package containing 100 million yen (about US$1 million) and a note that she is now a contestant in the Liar Game Tournament. In this fictional tournament, contestants are encouraged to cheat and lie to obtain other contestants' money, with the losers forced to bear a debt proportional to their losses. When Nao's first opponent, a trusted former teacher, steals her money, she seeks assistance from a
con man named Shinichi Akiyama. Though they manage to defeat him, Nao and Akiyama decide to buy out his debt and advance through different rounds of the Liar Game Tournament against merciless contestants, while at the same time attempting to free their opponents from debt and defeat the Liar Game organization from within.