Usogui follows a high-stakes gambler known as "The Lie Eater" who is obsessed with becoming the leader of a secretive underground gambling syndicate. The story is centered on brutal psychological and physical gambling matches where the protagonist uses his ability to detect lies to survive and outwit dangerous opponents. Readers enjoy it for its incredibly complex and unpredictable mind games, deep strategic battles, and the intense rivalry between the main character and his nemesis, the "Leader of the Library."