Student Council member Sakura Miharutaki faces off against a gamble crazed, unruly student. Mary's scheme backfires when an unexpected guest shows up.

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."

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