When Charlie McDowell began sharing his open letters to his noisy upstairs neighbors--two impossibly ditzy female roommates in their mid-twenties--on Twitter, his feed quickly went viral. His followers multiplied and he got the attention of everyone from celebrities to production studios to major media outlets such as Time and Glamour. Now Dear girls breaks out of the 140-character limit as Charlie imagines what would happen if he put the wisdom of the girls to the test.