Rob Fleming
Rob, the protagonist, is a chronically single man who finds his fulfillment in music. He's a collector of mix-tapes, devoting most of his attention to ranking songs and mentally cataloguing these rankings. After his most recent girlfriend leaves him, Rob decides to look back through his long list of relationships and discovers a disturbing trend. He embarks on a journey of self-recognition and decides to accept responsibility for mistakes he's made in past relationships which definitely contributed to the break-ups. With this realization comes a recognition of how badly he wishes to keep Laura in his life, so Rob tries over and over to prove to her how much he has changed. Eventually his efforts are rewarded when, after her father's death, Laura agrees to give Rob a second chance.
Laura
Laura leaves Rob because he's self-absorbed. He fails to demonstrate even a moderate level of commitment, despite her openness and readiness to commit longterm. She pursues an older, more reliable man after Rob, but she still cares for her ex. After losing her father, she feels compelled to pursue more meaningful relationships. Seeing this same motivation reflected in Rob's various changes since their breakup, she agrees to date him again, even moving in with him.
Laura's Dad
He was a reliable guy who always saw the best in Rob. His absence reminds everyone who knew him how powerful a person can be who chooses to extend unconditional love. He inspires Rob to improve himself and Laura to offer forgiveness.
Dick & Barry
Dick & Barry work for Rob at his record store. They're low-key cats who really just love the music. With slow business, they mostly spend their days engaged in passionate discussions about favorite artists and quality testing the tracks.
