To All the Boys I've Loved Before by Jenny Han
Lara Jean has kept all the love letters she's ever written. Whenever she's trying to fall out of love with a boy, she's always written him a letter, put it into an envelope and addressed it, but not mailed the letter. It's a great system, until one day her little sister mails them all.
Now all the boys Lara Jean has loved are coming to find out more about the girl who wrote those letters. Including her older sister's ex-boyfriend.
(Very big oops.)
Sweet and funny, this story is bigger on the inside. The relationship between the sisters is complex and believable. The coming-and-going of boys is realistically confusing for Lara Jean, who has never had a boyfriend--or a date--before. The rumor mill surrounding the school ski trip is absolutely ripped-from-the-halls-of-your-high-school.
And the ending...just stops.
Ahhhh, because book #2 in the series (it's a series??) is set for publication in April 2015. I guess we'll just have to wait and find out what happens next.
(I hate waiting.)