ABANDONED. Book about high schoolers who have the same name and maybe a doppelgänger of some sort?

[Noah]

Ok so my girlfriend remembers this book that she read way back in the day about some high schoolers dating and they had some generic name that applies to guys and girls like Taylor or Sam or something. And then they break up or something but at the end get back together and the guy is like "she seems like a totally different person" and it's because she is, she just looks exactly the same or something similar. That's all she remembers, if you guys can find it, that'd be awesome!

[Kris]

Noah, I moved your request to the Unsolved folder because you're looking for a specific book.

What year did she read this book? This will help narrow down the search.

[Noah]

I believe she read it about 9 years ago.

[Lobstergirl, au gratin]

Noah, are you still looking for this or did you find it?

[Kris]

No response, moving to Abandoned folder.

Noah (OP) was last active on the site in August 2018.