Theatrhythm Final Fantasy: Curtain Call, Nintendo 3DS.
Well, the good news, which is also the bad news, is that most Precure seasons are completely disconnected from one another. That’s good news because it’s The Franchise That Never Goes Away and if you had to start from the beginning and watch them all straight through it would take some ridiculous amount of time, and it’s bad news because you have like nine different possible starting points to decide between.
Personally my recommendation would be to start with the current season, Happiness Charge Precure. It’s just gotten into the double digits, so it’s not quite as easy to catch up as it would have been a month or two ago, but it’ll still be relatively easy, and if you like what you see you’ll be ready to dive right into the fandom and you’ll understand what’s going on. It’s also turning out to be one of the stronger seasons so far, with opinions overwhelmingly positive.
Thoughts on other seasons (in chronological order so I don’t have to try to rank them), which may or may not be particularly informative, below the cut.