"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, while those who fail face severe consequences, often becoming indebted "house pets" to their peers. The story centers on Yumeko Jabami, a transfer student whose unassuming demeanor masks a compulsive and fearless gambler. Yumeko thrives on the thrill of high-stakes games, often risking everything for the sheer excitement of the gamble, regardless of the odds.

The academy is dominated by the Student Council, led by Kirari Momobami, the enigmatic and calculating president. The council enforces strict rules and oversees the gambling system, ensuring that the hierarchy remains intact. Yumeko's arrival disrupts this order, as her unpredictable and reckless gambling style challenges the council's authority and exposes the flaws in their system. Her actions inspire other students to question the oppressive structure, leading to a series of intense gambling battles that test both skill and psychological resilience.

Key characters include Ryota Suzui, a former house pet who becomes Yumeko's ally and observer; Mary Saotome, a cunning gambler who initially opposes Yumeko but later forms a complex relationship with her; and various members of the Student Council, each with their own motivations and gambling specialties. The narrative explores themes of power, manipulation, and the psychological toll of gambling, with each game serving as a microcosm of the characters' struggles and ambitions. The series balances high-stakes tension with moments of dark humor, creating a compelling portrayal of a world where risk and reward dictate every action.