Rio, is a dealer, with supernatural luck, at Howard Resort. She has a special card called a "gate". She wins other gates by battling gate-holders in wacky gambling games. She needs to collect all of the "gates", for reasons.
The story beats are pretty standard but the gambling battles are pretty flashy. There's a good selection of characters, from androids to ghosts, that are moderately developed. The fanservice is plentiful but not full topless.
Overall, it's functionally competent and amusing, but probably won't become a favorite. I only gained interest in it because Rio is featured in the game Warriors All-Stars.