Nina is just a few months out from her 16th birthday. Her best friend is excited about it: when they turn 16, they'll be legal to have sex! And be chosen for the FeLS program! [Female Liason Somethingorother, basically escorts, I think, for government officials?] It's a way out of their Tier 2 lives, anyway. Nina is less than thrilled: being 16 means men can force themselves on her pretty much whenever they want with no repercussions. Things are going poorly enough for her already, but then her mom is killed, and right before she dies she tells Nina that her late father is actually still alive and she needs to bring him a particular book. No easy task, since her mother was possibly working for a resistance movement while Mom's abusive boyfriend is a government agent. Kidnapping, stalking, conspiracy, you name it, until the book mercifully ends. 
 I want to say there's a big point here in the whole "at 16 girls can legally have sex" and in the caste system, but that part of the world is never really explored. There's talk (in the "As you know..." style of dialogue) about how the world is vegetarian now, but no discussion of when the world became so misogynistic as to openly objectify young women and establish government programs for sex slavery. (Wait, that was supposed to be a big reveal, except it's totally obvious from the beginning, so idk.) Nina's best friend, the boy-crazy airhead, is basically slut-shamed at every opportunity, from the way she dresses to her flirting to her desire to be chosen for the FeLS program (somehow not guessing what the "Female liasons" might do). Advertising is omnipresent (again, no commentary on the society; it's just there), and the class system supposedly allows for no blending among the classes, except that Nina and her friends range across the whole spectrum. 
 Overall: not something I can recommend in any capacity, really. The dystopian elements are so underrepresented that it seems a stretch to even list this as dystopian. It's not even background; it's just not there.