While Purity is very different from Jackson Pearce's Fairytale Retellings series, it was still a wonderful story. Shelby made some promises to her mother before she died, and we see her struggling to keep all three of those promises. The promises pretty much control Shelby's life, and treats them as if they are binding. Her promise to listen to her father conflicts with trying to live her life with restraint...and the main clash between those two happens when her father wants her to take part in the Princess Ball, where she has to vow to live a pure life. 
 At times Shelby's struggle seemed pretty trivial, and I wasn't a huge fan of how she treated her father. She listened to him, like she promised her mother she would, but she didn't actually hear what he was saying most of the time, and she often ignored when he was trying to actually get to know her. It frustrated me that Shelby was so nonchalant about her father's interest in her life. I definitely wanted to shake her more than a few times, and this behaviour was the only thing that actually bugged me about Purity. Although...I'm sure for most girls, this is how they'd react as a teenager. I might have been in the minority with wanting to actually hang out with my parents when I was Shelby's age. :P 
 That being said, I was so happy once Shelby actually started giving her dad a chance! While she still didn't want to do the Princess Ball, she did become more involved with it because her dad wanted her to, and she also took more of an interest in getting to know him, too. I absolutely loved seeing them bond, and I thought that Shelby's dad was awesome! I'm not sure if I'd want to do a Princess Ball either, but I defnitely wouldn't mind the chance to get to know my dad better. The relationship between Shelby and her dad was the best part of Purity for me, and I loved that by the end of the book they both knew each other a lot better....and they were actually communicating!!! ;P 
 Along with the father/daughter relationship, I really enjoyed Shelby's friends, especially Jonas. ;) I loved Shelby's voice in the story, and definitely enjoyed getting to read her story. It was funny, and overall it was a rather heartwarming story. :)