The protagonist and 16-year-old narrator of the story, Miguel is the younger of two sons born to the marriage of a white, American mother and a Mexican father. He frequently alludes to his relationship with his 17-year-old brother, Diego, which appears to vacillate between hero worship and being the reluctant victim of extreme roughhousing at the hands of his older sibling.

Although he strives to maintain a disaffected, “cool” demeanor, Miguel does very well in school and has attained a cumulative GPA of 3.4 in high school. He enjoys reading, but does so furtively, in an effort to avoid ridicule by his brother. Miguel’s narrative takes place in the format of a journal that he writes describing his experiences over the course of several months. The diary begins when he describes being sentenced by a judge to a term of one year to be served in a group home, with the caveat that the boy maintain a daily journal in order to help his counselors understand him. The nature of Miguel’s offense is not entirely revealed until the conclusion of the story; nonetheless, the reader quickly becomes aware that something has changed his relationship with his older brother, and that Miguel is currently out of touch with his mother.