"Kakegurui" is set in Hyakkaou Private Academy, an elite institution where students are groomed to become future leaders of society. However, the school operates under a unique hierarchy determined by gambling. Wealth and status are secondary to gambling prowess, and students who excel in games of chance rise to the top of the social ladder. The Student Council enforces this system, using its authority to maintain order and exploit those who fall into debt.

The narrative centers on Yumeko Jabami, a transfer student who quickly disrupts the academy's established order. Unlike her peers, Yumeko gambles not for status or wealth but for the thrill of risk itself. Her unorthodox approach and seemingly supernatural intuition make her a formidable opponent, challenging the school's top gamblers and exposing the darker aspects of the system. Her arrival sparks a series of high-stakes games, each escalating in intensity and psychological complexity.

Key characters include Mary Saotome, a cunning and ambitious student who initially underestimates Yumeko but later becomes a reluctant ally. Kirari Momobami, the enigmatic and ruthless Student Council president, serves as the series' primary antagonist, orchestrating many of the challenges Yumeko faces. Ryota Suzui, a passive observer and Yumeko's first acquaintance at the academy, provides a grounded perspective on the chaotic world of Hyakkaou. Other notable figures include Midari Ikishima, a deranged gambler obsessed with life-and-death stakes, and Itsuki Sumeragi, a manipulative strategist who thrives on psychological warfare.

The plot unfolds through a series of gambling matches, each revealing more about the characters' motivations and the academy's corrupt structure. Themes of power, manipulation, and the psychological toll of gambling are explored as Yumeko navigates the treacherous environment. The series balances intense, high-stakes games with moments of dark humor and surrealism, creating a distinctive tone that sets it apart from traditional school-based dramas. As Yumeko continues to challenge the status quo, the narrative delves deeper into the academy's secrets, culminating in confrontations that test the limits of ambition, morality, and human nature.