Well, this show was mostly what I expected- an excuse for fanservice where the main character, Rio, dresses up in revealing costumes. It’s an adaptation of a Pachinko game, so it didn’t hold much promise to begin with. Umi Monogatari was also based on a pachinko game and managed to build a good story with its limited premise, but the creators of Rio Rainbow Gate don’t really seem to be trying for this (the story is even set in a casino, how creative!).
With that said, this show did have me laughing, especially at the ending. It’s of the so bad it’s good variety, but still, if they manage to keep it up, it could be a decent show. I doubt they’ll be able to for an entire season though, and the show will probably descend into pointless fanservice and insipid drama. The only feature of Rio’s personality seems to be protruding from her chest, and I’m going to predict there will be some tedious story involving Rio’s mother. I’ll probably keep watching this one but am not too optimistic.