Children from influential families in politics and businesses attend the Hyakkaou Private Academy. There, the hierarchy of the students are classified by a series of games. Students that win the games are on the ruling side and the students who lose become slaves. One day, a mysterious girl, Yumeko Jabami (Minami Hamabe), is transferred to Hyakkaou Private Academy. She looks pure and pretty, but she is actually a compulsive gambler and seeks out the thrill of taking calculated risks.
Episode 1
Unaware of her new school's ways, transfer student Yumeko Jabami is offered a high-stakes game of rock-paper-scissors against her classmate, Mary.
Episode 2
Having lost her initial buy-in against Mary, Yumeko raises the stakes even higher by reburying into the match with an extremely large bet.
Episode 3
Student board member Itsuki challenges Yumeko to a game of pairs. Rumored to have never lost in this game, Itsuki lays a shrewed trap agaisnt her.
Episode 4
Desperate to regain her status in the school hierarchy, Mary duels student board member Yuriko in a game of "life or death" as Yumeko looks on.
Episode 5
Yumeko takes Yuriko on and taunts her as if she knows something about the trap Yuriko has laid against her.
Episode 6
After a monumental outcome, Yumeko receives a cryptic file form the student board. Meanwhile, a card game for those heavily in debt commences.
Episode 7
Yumeko and Mary pair up for a game of Indian poker against Kiwatari, the class bully known for manipulating others through fear and intimidation.
Episode 8
Although able to repay her losses, Yumeko chooses to remain in debt in order to qualify for an official match with the student board president.
Episode 9
Yumeko agrees to go up against the Beautification Committee Chair in an ESP card game involving Russian roulette.
Episode 10
A nervous Suzui serves as dealer for Yumeko's deadly duel with Midari. Meanwhile, student board member Manyuda summons Mary for a surprising proposal.
