Diane Nguyen is a fictional character from the animated television series BoJack Horseman. She is portrayed as a Vietnamese-American writer and a close friend of the show's main character, BoJack Horseman. Diane is known for her intelligence, strong moral compass, and struggles with self-identity and mental health throughout the series. In the show, Diane often grapples with her career and personal relationships, reflecting the complexities of modern life. She is a significant voice for social issues and often serves as a counterbalance to the more self-centered characters, highlighting themes of empathy and personal growth.