Yuri, the former heiress of a company, finds her father's business bankrupt. To repay the debts, Yuri must compete in mahjong and continue to win. Can Yuri truly defeat her formidable opponents?
The story is about the weakest Demon King, who battles rival magical girls, angels, and the Demon King of Hell, and grows up trying to subdue them. If you win, you can acquire your opponent's cards and incorporate them into your own deck.