The majority of Mexican WhiteBoy takes place in National City. National City is a southern suburb of San Diego, and it is not known for being especially affluent. Danny is the story's protagonist, and he moves in with extended family in National City for the summer. Danny is incredibly shy, but he is also an excellent baseball player. This puts him at odds with Uno very early in the story. Fortunately, Danny and Uno hash out their differences and become strong friends within a matter of weeks. This close friendship allows readers to be a part of Uno's life and see his struggles, thoughts, and dreams as well.

Uno's father is Senior, but Senior does not live in National City. His former gang life didn't mesh well with Uno's mother, and the couple split up. Senior now lives a few hours north in a much more affluent part of southern California, but Senior religiously drives down to visit with Uno on a regular basis. On one such trip, Senior offers Uno the chance to leave National City and come live with him and his new wife. Uno is very much tempted by the offer, but it comes with a catch. Uno has to earn enough money before Senior will allow the move to happen. Senior believes it is his way of teaching his son how to be a better man and work for things. Uno's main source of the money comes with Danny's help as they run a baseball hustle against other players.