Diane is a nice, well-meaning, misunderstood intellectual, and a Vietnamese-Americanthird-wave feminist from Boston. In the, Diane is hired by BoJack's publisher as a ghostwriter for his memoir, having previously written a biography of BoJack's childhood hero, Secretariat. Diane and BoJack become friends, and BoJack develops romantic feelings for her, only to find out she is dating his rival Mr. Peanutbutter. In the episode "Live Fast, Diane Nguyen", she and BoJack travel to New York together to meet with the book publisher, but take an unexpected trip to Boston after learning about Diane's father's death. Later, when they return, Mr. Peanutbutter proposes, and the two become engaged. The couple marries soon after, and Diane finishes BoJack's book. She struggles throughout her career to get recognition for her writing, and travels to the war-torn Republic of Cordovia to make a difference, but discovers that this life is not for her. Ashamed of returning to her then-husband at the time, she develops a severe bout of depression, during which she drinks heavily, smokes pot, and sleeps disheveled on BoJack's house. She is able to reconcile her feelings with Mr. Peanutbutter and gets a job at VIM ghostwriting tweets for celebrities. She is subsequently fired from VIM, and is hired to write for a feminist blog. During and after Mr. Peanutbutter's run for Governor of California, their marriage begins to falter and, in season 5, they divorce, although they still remained friends. Diane moves into a run-down studio apartment upon separating from Mr. Peanutbutter. Later in the season, she begins ghostwriting the TV seriesPhilbert, which BoJack stars in, after showrunner Flip McVickers develops writer's block. Though the first season of the show is a success, BoJack, under the influence of painkillers, gets involved in a scandal with his co-star, resulting in the show's cancellation. Diane encourages BoJack to enter rehab, and she sends Bojack to the rehab clinic after offering some final words of encouragement. In season 6 Diane dates her coworker, a Bison named Guy who has a son and is divorced, and decides to move from LA to Chicago to live with him. She begins writing a new memoir that leads her back into her recurring depression. She treats this with antidepressants these hinder her progress on her memoir, which she eventually abandons in favor of a teen fiction series called Ivy Tran: Food Court Detective that she wrote when she was high from her meds. She eventually moves to Houston with Guy and is revealed in the series finale that she married him. She ends the series having what will seemingly be her last conversation with BoJack, telling him that she doesn't regret that she was close to BoJack and for her life in LA, but that she is ready to move on and presumably cut him out of her life.
Reception
Diane has been praised as one of the strongest characters in the series, as it has shown her personal growth in addition to that of BoJack, the lead character. She has also been considered the "voice of reason" in the show, with her story arcs also shedding light on real-world issues. However, the show has also received criticism over its allegedly underwhelming portrayal of Diane and Asian American culture, especially in the fact that Alison Brie, a non-Asian actress, voices the Vietnamese-American Diane.
