Lacking in gambling skills, Tsuzura Hanatemari finds herself at the bottom of the food chain — until one day, an old friend transfers to the academy.

On the brink of becoming a house pet, Mary must find a way to earn money. Trust is on the line when she and her friends attend a "coupling party."

With a traitor in their midst, Mary struggles with trusting her friends. Meanwhile, the opposing boys' team argues over whether to rejoin the game.

Aoi attempts to lure Mary into his Full-Bloom society. Joining forces with Mikura, Sakura plots to undermine Mary through a gambling match.

Sakura and Mary brace themselves for the final game. In desperation, Mary asks her friends for help, using whatever means necessary to win.