I read this book and the one before it as the first ones in this series. There was quite a bit of stuff I didn't get with the references to the other characters, but it wasn't bad enough that I didn't stop reading and following along.
I suppose if I had read the other books before hand, I wouldn't feel as if the ending was confusing as well as just falling flat.
I gave it 4 stars because Pia and Kristoff were fun and cute together, but the story line was just blah.
Maybe after reading the rest of the series from the beginning, I might in hindsight, come to really like their story.