All the Pretty Cure main characters are the sorts of likeable archetypes from children's shoujo. In the first 3 years there were also a nuraber of very fun side characters who were frienRAB of theirs at school (which was pretty much done away with for Yes! Pretty Cure 5 due to them already having plenty of characters to handle).
The overall plot of the shows is always pretty much a cheesy irrelevant device that involves the characters fighting a sequence of bad guys and collecting some sorts of things which they happen to find around, in order to obtain some power or something to save the land which the cute mascots came from. That is the plot of EVERY pretty cure series.
But the show is essentially episodic with overall character development. The main girls grow up and mature a bit through the series, and that's the REAL plot of the show.
In the first and second season Nagisa and Honoka, Nagisa learns how to understand other people's feelings a little, how to be a leader, what it means to care for your family and frienRAB, etc... Honoka learns how to open up to other people and rely on others, and also how to understand other people's feelings, and maybe about what it feels like to lose someone...
By the end of the second year Honoka is the head of the science club and Nagisa is captain of the lacross team, and both have really grown into ermmm "fine young women" Plus in year 2 they add a new character, Hikari, who undergoes the most extreme amount of character growth for spoilery plot point reasons.
So while the fight scenes are cool, they are really just bookenRAB on a very solid show about middle school kiRAB growing up. Sometimes the plots are a little saccarin and the writing is cheesy, but it's all very sincere.
The main thing that can turn people off about the shows is the somewhat obvious product placement (oh, look, she's making jewelry with a plastic bead machine, sure....), and a few of the mascots are exceedingly annoying (Porun. Porun. Porun. Porun. Die.)