Honestly, I didn't like it that much myself, but for those who find incredibly convoluted manga plotlines appealing (and when we're talking about manga series, which can sometimes be very drawn-out, there is actually an audience for this)this will have a lot of drama and twists to keep them hooked.
Follow this plot if you dare...Haine, the heroine, was coldly sold by her father into adoption to another family. This spurs her into a career of infamy as a yanki (juvenile delinquent) until an encounter with her crush inspires her to change her ways. She gets a job at the school to help her adopted family which has fallen into hard times, but ends up with a surprise "promotion" to student council bodyguard. And who is she sworn to protect most of all? Her crush, Shizumasa who rules the Student Council (and the school) as "Emperor". So far so good, but what follows is like a big mix of the most preposterous gimmicks from soap operas---mistaken identity, secret twins, boys masquerading as girls, love triangles, rivalries, rumors, conspiracies, and more. The cast of main characters (mainly student council members but also assorted family members and outside love interests) is numerous and a bit hard to keep track of, even with the sidebars profiling each one in Volume 1. Haine is scrappy and likeable overall, though her feelings for Shizumaya are about equitable to the soppiness Bella displays for Edward in Twilight--so be prepared.
Maturity (Vol. 1): Scant mild, cartoonish violence, no obvious fan service, sex, or nudity. Haine fantasizes about her crush once or twice, but it's all lead-up, nothing happens, we see nothing really. Two boys kiss in one scene but it's not what it looks like. Overall, all smoke, no fire--and not even much of that. It's more about the romance (and one-sided, unrequited romance at that as Shizumasa is standoffish towards Haine)than anything. Volume 1 acceptable for 11-12+