The story is simple and heartwarming, though it is a typical high school drama. Henry Li and Alice Sun are academic rivals, and Alice hates Henry, to the core. But when one day Alice simply turns invisible, there's no one she can possibly go to but him. The story progresses, and Alice is almost dumb regarding romantic matters, and though it is promoted as a romance, I think the author's main objective was to show the disparity, the struggle, the almost-impossible-climb to 'success' as it is perceived, the inner fears of middle class students, that they simply will not be enough. And I think there, she has done a wonderful job.
Now, we really don't know how Alice turns invisible, or if after the incident, the turning-invisible-out-of-the-blue thing stops, and it would have been better if we knew why she was turning invisible. In the philosophical point of view, maybe it is because that is Alice's worst fear.
Overall, the book is recommended as a light, fun, feel-good read and I really liked it. No spice, and other than a kiss, it's clean. I do recommend this book as a quick read, to get you out of a reading slump.
The writing is very simple, not very poetic, and if you've just gotten into reading, this is a highly recommended read.