Sugar follows the story of Miguel Santos a.k.a. Sugar, a Dominican pitcher from San Pedro De Macoris, struggling to make it to the bug leagues and pull himself and his family our of poverty. Playing professionally at a baseball academy in the Dominican Republic, Miguel finally gets his break at age 19 when he advances to the United States' minor league system; but when his play on the mound falters, the begins to question the single-mindedness of his life's ambition.

The baseball academy where Miguel Santos has been training as a pitcher since he was signed at age 16 is a breeding ground for major league talent. Living at the facility during the week, players go through rigorous daily training, while scouts observe and grade their abilities. Sugar's uncommon ability on the mound is apparent, but there are thousands of teenagers across the island just like Miguel, all of whom hope for the opportunity to advance to the United States minor league system - just the first step of many on an arduous journey to the big leagues.

Miguel spends his weekends at home, passing from the landscaped gardens and manicured fields on one side of the guarded academy gate to the underdeveloped, more chaotic world beyond. In his small village outside San Pedro de Macoris, Miguel enjoys a kind of celebrity status. His neighbors gathers to welcome him back for the weekend; the children ask him for extra baseballs or an old glove. To his family, who lost their father years before, Miguel is their hope and shining star. With the small bonus he earned when he signed with the academy some time ago, he has started to build his family a new house - one that has a bigger kitchen for his mom and a separate room for his grandmother.

Jorge, the more veteran player and the only other Dominican on the team, also tries to help Miguel learn the ropes. However, despite the Higgins' welcoming efforts and Jorge's guidance, the challenge of Miguel's acceptance into the community is exposed in small ways every day, from his struggle to communicate in English to an incident of casual bigotry at a local bar.

Miguel's domination on the mound masks his underlying sense of isolation, until he injures himself during a routine play at first. While on the disabled list, Jorge his one familiar connection to home in this strange new place is cut from the team, having never fully regained his ability following off-season knee surgery. The new vulnerability of Miguel's injury, coupled with the loneliness of losing his closest friend, force Miguel to begin examining the world around his and his place within it. Pressure mounts when Salvador, a young pitching phenom who used to play with Miguel, is brought up from Dominican Republic to join the team. Miguel's play falters, and the increased isolation begins to take its toll on him. As his dream begins to fall apart, Miguel decides to leave baseball to follow another kind of American dream. His odyssey finally brings him to New York City, where he struggles to find community and make a new home for himself, like so many before him.