Joshua Park is the novel’s male protagonist. A tall, black-haired, handsome man in his twenties, he is Lauren’s husband, and half of the novel’s chapters are written from his third-person point of view. Josh resembles his biological father, who has Pakistani and Euro-American heritage, more than his mother, Stephanie, who is Korean. He identifies with his neighbors, the Kims, who are like parents to him, and enjoys when people recognize his Korean heritage. Josh graduated with a BFA in industrial engineering from RISD (summa cum laude), an MS in biomedical design from Brown (summa cum laude), and a PhD in mechanical engineering from MIT. His successful design of medical devices both during and after school garnered him a reputation as a genius. Social awkwardness, laser focus, and reclusiveness accompany his ingenuity, and Josh experiences emotions intensely at times. All of these circumstances led to an autism diagnosis during childhood, and he manages intense emotional moments in adulthood through repeating a sentence aloud or using a punching bag.

Josh’s round characterization adds complexity to the story and his relationship with Lauren. At the novel’s beginning, Josh is grief-stricken, deeply affected by losing Lauren.