Twelve-year-old Sunny St. James has a new perspective on life after she gets a heart transplant. Now that she's healthier, she sets out to do things she could never do before, which includes making a new best friend and kissing a boy. But as her plans progress and she seems to be moving in the right direction, Sunny's mother comes back into her life, leaving Sunny's new heart heavy with feelings she's tucked away for years. And as she enjoys her new best friend, Quinn, she begins to wonder perhaps she's not interested in kissing boys after all.