Althea and Oliver by Cristina Moracho is a young adult book, but it easily crosses over into the "adult" category, with an appeal wider than just the teen readers I initially envisioned.
Althea and Oliver have grown up together and always been best friends. They both come from single parent homes and rely on each other for companionship. However, as they get older and are in the midst of their high school years, their relationship is changing. Althea wants more than to be "just friends," while Oliver isn't sure yet. Although this is not a unique plot, Moracho does a great job of creating two characters that seem so real and human that I was invested in this story from the beginning.
The addition of Oliver's struggle with Klein-Levin Syndrome, a sickness that causes him to sleep excessively for sometimes weeks at a time with little or no time awake, adds another layer to this story.
Most people will be able to relate to Althea and Oliver and their relationship, and will love this story of a friendship that has grown and changed over a lifetime.