Only a Kiss by Ines Bautista-Yao
You can purchase the book through the link below.
I didn't want to stop reading, missed a step, and almost fell down the stairs. Deadly book.
The strength of this book is in the characterization and the believable narration which ages with the kids. They feel like kids, then teens, then young adults. They are likable and relatable throughout, with believable foibles as well as strength.
I liked that this kept its non-US setting without feeling confusing to someone who has never been there, just enough non-English words thrown in to give it character (there's a glossary in the back, but I never needed it).
My only two small quibbles were occasionally the story would skip forward in time and then catch us up with "what we'd missed" in the last few years through a quick "sum up" narrative. Once or twice I lost track of the timeline because of this, but only for a moment. Also, if you are considering this for a younger reader, there is some drinking at parties for fairly young characters.
I really enjoyed this lighthearted read and finished it quickly. It's a happy, hopeful, interesting love story.