Everything in Cassia's life has been planned by the Society, and she's never doubted that plan. In fact, she's usually been happy with it, especially when she found out that she was to marry her best friend. Starting with her grandfather's death when he gives her something he never should have had, and later when she sees another boys face on a device that should only have shown her match, Cassia's faith isn't quite so strong anymore.
Cassia: At first, Cassia believes the society knows best, so even when she beings to think otherwise she's hard pressed to rebel. At times, I found this a bit frustrating. I thought she could have rebelled a bit more; after all, her grandfather did and wasn't caught. She only really rebelled when it came to love. I withhold judgment on this behavior and the strength of her character until I read the next book.
Xander: He seems almost too good a guy. He loves Cassia and stands by her no matter what. He sees Ky for the person that he really is, and hides this from the Society, since Ky obviously doesn't want them to know. He always seems to protect those around him, even when he has reason to doubt them. This is an admirable quality, but sometimes I wondered if he wasn't too nice.
Ky: A boy from outside the city, because of something his parents did. The society deemed him unfit for marriage or a good job, but he willingly lives the life that the Society set for him, hiding his true strengths. Only with Cassia does he allow himself to be himself, but even from Cassia, he doesn't reveal everything. Sometimes I had to wonder what made Cassia choose him over Xander, he's a nice guy who shows her things that she'd never seen before, but the amount of time they spent together was so limited.
While I wish Cassia had rebelled a bit more and I have my doubts that the Society could really predict as much as they do, the concept makes me think: "What if they could? What would I do in her place?" It's really these questions that make me enjoy the story so much. It makes me curious and I want to know more about what happens to Cassia and what will happen to the Society, especially when you see what they predict accurately and what they don't. Just how strong is the Society? I can't wait to read book 2 and hopefully learn more.