Regulars of the Jianba barbershop in the southern Chinese city of Zhuzhou recently found it shuttered, with a curious note taped to the door.

Dear customers: I got a call from my daughter yesterday. I have been away from her so long she doesn't even know how to call me 'Daddy' anymore. . . . I beg you for a week off to visit my family."

The letter, photographed by a passerby, was posted on the Chinese equivalent of Twitter and quickly went viral. It reflected a growing angst in this country over "left-behind children."