Wish I Were Here by Wiesner, Melissa

Opposites attract when a buttoned-up professor and carefree doorman must restore a magically missing identity in this sparkling romance, perfect for fans of Sophie Cousens and Ashley Poston.

For type-A mathematician Catherine Lipton, growing up with a free-spirited single dad who worked part-time as a clown was more than a little stressful. So as an adult, the only place she'll allow for variability is in her data sets. Everything in Catherine's life is ordered, from her lists to her lesson plans at her new job as a college professor. Catherine's carefully calculated life goes awry, though, when the university's human resources system rejects her employment paperwork. Soon after, her credit card is declined. At the Social Security office, Catherine makes a shocking discovery--she's disappeared from the government's records, and there's no evidence she exists at all. Catherine can't seem to convince anyone she's a real person, even though she's standing right there in the flesh.

Catherine knows she can't count on her dad, and the university is only concerned with who will teach her classes. The one person who offers to help is Luca Morelli, her attractive but aggravating doorman who spends more time flirting with Catherine's neighbors than he does enforcing the building rules. The older residents might fall for Luca's charm, but if he can't keep bikes out of the lobby or put packages in their designated area, how can he help Catherine get her life back?

Left with no other options, Catherine reluctantly agrees to enlist the help of Luca's well-connected Italian family. Soon, Catherine finds herself following Luca into a smoky bar to meet the Mafia, breaking into the records room of a local hospital, doing a little light stalking, and having a surprising amount of fun. She also finds herself growing closer to Luca, who makes her laugh and challenges her well-ordered ways. As Catherine begins to unravel the mystery behind her missing identity, she may discover that the "real" Catherine is someone she never expected.