Rio and Dana follow her ferret, Chip, to a casino where the mysterious Joker is holding Howard captive. She challenges Rio to a game of blackjack in order for her to escape her Roll Ruler, which forces them into a draw at every play.
Rio and her friends enter Goldschmidt Kingdom and start winning big in the various attractions in order to be able to buy back the resort. However, Mint's bear Choco goes missing, so Rio goes with her back to the casino to search for it.
After publicly announcing the terms of the Gate Battle, Howard takes Rio and the others on vacation to an island town to relax before the battle. While looking for Rio, Mint meets an old man, who explains Rio used to come to this place with Rina and Risa when she was young.