Smile PreCure!, or Glitter Force if you were on Netflix, is a magical girl anime created by Toei Animation (the studio begind Dragon Ball!) in 2012. The show revolves around Miyuki Hoshizora and her friends Akane, Yayoi, Nao, and Reika becoming magical girls and fighting against Lord Pierrot's disciples who are trying to give the world's story a bad ending. [In Netflix's English dub, the characters were renamed Emily, Kelsie, Lily, April, and Chloe. For this site I use their original names.]
If this sounds like just a sterotypical magical girl show, that's because it is! PreCure is actually a massive franchise in Japan, going back as far as 2004, and introduced the idea of magical girls who fight with martial arts and their bare hands as opposed to just waving wands around. This format proved to be succesful enough to where PreCure is now massive in Japan, and still releasing a new themed series every year. Smile was the only season to gain popularity in the U.S., due to its (questionable at best) Netflix dub. The theme for this season is fairytales!