Yunior is a Dominican immigrant who grows up in New Jersey before eventually building an academic career in Boston. He is charismatic and intellectually curious, possessing a deep love for literature and comic books. He struggles with fidelity and his treatment of women, behaviors heavily influenced by the hypermasculine culture modeled by his father and brother.

Rafa is Yunior's older brother, a tough athlete and neighborhood womanizer who embodies Dominican machismo. He refuses to help with domestic chores, expecting his mother to clean and cook for him. Stubborn and rebellious, he faces a severe cancer diagnosis that severely tests his intense, aggressive personality.

Yasmin is a hardworking Dominican immigrant who manages a team of laundry workers. Pragmatic and observant, she handles the practical challenges of building a life in the United States. She quietly monitors the letters her partner receives from his homeland, choosing to tolerate his divided loyalties to build a future together.

Mami is Yunior and Rafa's mother, a reserved Dominican woman who manages the family's domestic life entirely on her own. She quietly tolerates her husband's infidelity while cooking elaborate meals and cleaning for her ungrateful sons. She turns to intense religious devotion when her family faces medical crises.

Papi is Yunior and Rafa's authoritative father who brings his family to the United States. He is strict and deeply critical of his family, holding unapologetic views about his own infidelities. He forces the boys to stay inside all winter to learn English and enforces his rules through physical punishment.

Nilda is a teenager lacking a stable home environment, often seeking refuge at Yunior's apartment to avoid her alcoholic mother. She bonds with Yunior over comic books while pursuing a romance with his older brother. She frequently relies on the attention and resources of men to escape her poverty-stricken family life.

Miss Lora is a single, middle-aged Dominican neighbor and former competitive gymnast with a rebellious history. Having lived abroad and worked as a teacher, she is highly educated and extremely comfortable in her own skin. She treats the teenage Yunior with a tenderness he rarely experiences, leading to a complex and legally questionable dynamic.

Alma is a sexually adventurous, artistic Dominican-American college student. She loves independent music and takes pride in actively reclaiming her Dominican heritage. She expects honesty from her partners and reacts explosively when those expectations are violated.

Magda is a mixed-race Dominican American whom Yunior categorizes as a pure, "good girl." She is close to her father, deeply religious, and works as a teacher. When her relationship hits a crisis point, she agrees to travel to Santo Domingo to see if their bond can be repaired.

Flaca, whose given name is Veronica, is a bookish young woman from outside Paterson, New Jersey. She works as a teacher and holds an additional job at a publishing press to support herself. She is deeply generous with her time, frequently offering Yunior rides and inviting him over whenever he calls.

Ramon is a chubby Dominican man who works hard to establish a permanent life in America. He maintains a complex double life, attempting to purchase a home and build a future with Yasmin while remaining tied to the wife and son he left behind in his home country.

Pura is a recently immigrated Dominican girl who becomes involved with Rafa during his illness. She quickly elopes with him, causing immense friction within his household. She primarily seeks financial stability and proves unreliable when Rafa's health rapidly declines.