This series is infuriating. The plot is weak, the characters are bland, the protagonist is an idiot, there are things that do not make sense or would not happen in real life, but I can't stop reading it. Something is obviously wrong with me. 
 First Days is, surprise, about Sang and the guys during their first week of school. In my opinion, writing day to day gets boring, especially about something monotonous like school or work, so Stone decided that something extreme needed to happen every day. So here's what happens: fights, marriage proposals, shifty authority figures, Sang being an idiot, the guys being made targets, and a whole lot of gag worthy feelings. 
 Sang got worse, I think. Her home issues aren't really focused on because the majority of the book takes place at school. The most her mother does is make her sit on a stool and denies her a violin for music class. This is made up for by a constant bombardment of Sang's feelings. Every time one of the guys touches her, she has to comment on how it feels. There are constant mentions of how they smell, how they look, how they feel, to the point that it's ridiculous. She's naive, wondering if a goofy guy is serious when he proposes, and clueless, thinking all the touching the guys do to her is normal. Sang, do you ever wonder why they never get touchy feely with each other? Not to mention she throws herself into two fights full of guys that could kick her ass, but is praised for how brave she is. I'm pretty sure brave isn't the same as stupid, just saying. Sometimes she seems pretentious too, calling the people at school "kids" or "children" or something along those lines. Sang, you're fifteen. Most people refer to close-aged groups as "people around my age", not "teens", "kids", "twenty-somethings", "older adults", "elders", etc. Shut up. 
 I can't really say much about the guys. Back in my Introductions review, I said that you could tell Stone tried to make the guys different, but it fails because they all act the same. It holds true here as well. It seems like they all enjoy dating her at the same time, and she's too dense to realize that it's happening. 
 Speaking of guys, Blackbourne and Green... what the hell. They're nineteen. Green has a doctorate of some kind (probably not a medical degree because Sang asks and the guys laugh). They're both teaching at a high school. No way would this happen in the real world. "But it's silly fantasy!" you cry. NO. If you're going to write about a contemporary setting, make it somewhat realistic, okay? Nineteen year old men do not teach high school or have doctorates and if they do, it's definitely few and far, far, far, FAR between. When I was in high school, the youngest teacher we had was a twenty-nine year old woman and all the guys drooled over her. Nineteen years olds teaching high school would be a HUGE problem. Oh, but they have to be somewhat young (aka not over twenty), because they both have the hots for Sang. Green openly flirts with her in class, and Blackbourne finds her attractive, but can't focus on that sort of thing right now. GAG. 
 Actually, pretty much the entire male population wants in Sang's panties. She must be a succubus. Is this an urban fantasy novel? Either way, I'm not buying it. Even if she's pretty, she's an idiot. No wait, that's probably why everyone wants her. 
 (view spoiler)[In a pointless epilogue from Blackbourne's point of view, we find out that Sang was probably kidnapped as a baby: her birth certificate is fake and she doesn't have any type of records (school, medical, etc). This somehow makes her prime real estate and Blackbourne is desperate to adopt her into the Academy (which we still don't know what it is) before others discover her. Oh, and he has to mention that Sang has ruined his entire team with a look and he needs to recruit her or else they'll all fall apart. What the hell, I didn't realize immense stupidity was a super power. (hide spoiler)] 
 The only thing I liked was that Sang and Marie agreed to work together so they could escape the house and cover for each other. This was a nice change because it was toted around that Sang was the better sister because she didn't shift focus to Marie when she got caught, which is what Marie was constantly doing to her. 
 Another review likens this series to a trainwreck, and I couldn't agree more. It's so lame, and I can't help but enjoy it on some level.