Diane is an American writer, misunderstood intellectual, and third-wave feminist from Boston who lives rent-free with her well-off and famous husband, Mr. Peanutbutter.
Diane is a grown woman and one of the few main characters in BoJack Horseman that is a human. Diane has dark blue haired, light skin, and black-dotted eyes. Diane is typically wearing glasses, a green jacket with an arrow designed on each end near her abdomen pointing towards her center, a white undershirt with her cleavage and stomach slightly shown, and heels that almost reach her knees.
In Live Fast, Diane Nguyen it was revealed that Diane had a tough childhood, with her parents and brothers caring little for her. Her brothers tell BoJack about how they all took turns writing letters to her under the name Leo, then hired a hobo to pretend to be Leo and take her to prom.
She attended Boston University where she majored in Literature and Equine Studies. She is the author of Secretariat: a Life, The Rise and Fall of Strongheart and New York Times bestseller Tracing Zippo Pine Bar. She and BoJack, who hires her to ghostwrite his autobiography, initially develop a strong friendship that becomes strained after he develops feelings for her.
Her biography of BoJack, One Trick Pony, earned the Golden Globe Award for Best Comedy or Musical.
Diane is a nice, intelligent, nerdy, well-reasoned, third-wave feminist. Like BoJack, Diane had quite a tough childhood, having been raised in a house full of spiteful, goofing, lazy brothers and parents who didn't seem to be very affectionate towards her, hence her determined, dedicated and somewhat aggressive nature. This often enables her to put up with people like BoJack Horseman at the most trying of times. Although she can seem quiet and very much enveloped in writing, Diane has been seen to snap and lose her temper, which has been shown in the past to be quite violent. She also has a spiteful streak when provoked, leaking chapters of BoJacks biography against his will and accusing her husband of making things "all about him" (despite his selflessness) to cover for her own unhappiness with her life choices. In addition, Diane often tends to get dragged into BoJack's shenanigans, especially in Season 1.
- Her last name Nguyen is the most common Vietnamese family name but ironically most characters in the show have trouble pronouncing it.
- Even though she's a ghost writer, her name is on the books she wrote.