Imagine a high school where math and history are tossed in the trash, and the entire curriculum is just "how to develop a crippling gambling addiction." This is Hyakkaou Academy. The student body is a hive-mind of rich, sweaty idiots who bet millions on poker; if you lose, you become a "House Pet"—essentially a slave with a nametag. Into this madness walks Yumeko Jabami, a girl who looks innocent but gets... _way_ too excited about the prospect of financial ruin. She’s not here to win money; she’s here to destroy the hierarchy while making faces that look like demon masks.