Beware of rampant spoilers of season 1 and 2! While the majority of spoilers involving plot points of the current season will be hidden, this is not consistent depending on the situation, with just the presence of certain tropes being spoilers. Enter the folders at your OWN RISK.
This article is for Netflix's first original animated series Bojack Horseman's character.
A nerdy, socially awkward writer from Boston, who is Mr. Peanutbutter's girlfriend/wife and BoJack Horseman's good friend. Diane is initally tasked with writing BoJack's memoir, but the two become close throughout, as she spends a lot of time with him and relates to the horse's depression and struggles, as she also suffers similar issues to him.
- Alone in a Crowd: She doesn't like big parties and can often feel uncomfortable by how easily she's overlooked. Mr. Peanutbutter throwing one for her 35th birthday in "After The Party" (and insisting on keeping it alive far beyond the comfortable) is one of the catalysts of their fight.
- Ascended Fangirl: Being a fan of Horsin' Around as an escape from her horrid family life, Diane eventually grows up to meet and write the biography of its star, BoJack Horseman.
* Bare Your Midriff: With her original outfit her white shirt leaves the bottom of her stomach exposed.
- Being Good Sucks: Fighting for good causes in a society as shallow and self-serving as Hollywoo sucks, as most people just demonize her as a Straw Feminist and Soapbox Sadie who needs to shut up and go away. A surprising number of episodes end with her giving up her squeaky-clean morals just to find some peace or get along with her friends and coworkers.
- Black Sheep: Not literally (since she has a black sheep adoptive brother), but she fits the figurative meaning of the trope, being The Unfavorite in a family full of Jerkasses.
- Butt-Monkey: Diane came from a family in which she was the most tortured one, with everyone ganging up on her, eventually growing up, moving to Hollywoo and being constantly disillusioned about ideals and people, traumatized by events other people often overlook, constantly ignored and berated and often feels useless and unimportant believing she will never reach her full potential or make an impact on the world.
- The Conscience: Usually provides a moral and sensible contrast to BoJack's self-centered, off-the-wall antics and schemes, as well to her husband's obsession with positivity and desire to cling to a perfect reality.
- Dark and Troubled Past: Diane's upbringing wasn't the best, to say the least. In the present, her mother constantly guilt trips her about leaving her family... a family who did nothing but torment and belittle her. There's also Diane's father, who contrary to what she said to BoJack, was just as abusive as BoJack's parents.
- The Dutiful Daughter: She returns to her hometown to bury her dad and is the only one to organize the funeral or care to assist. That, despite the fact that her family has never done any favors to her.
- Embarrassing Nickname: She'll always be known as "Cry-ane" by her brothers.
- Embarrassing Slide: Despite Diane's pleads not to, her brothers end showing Bojack the "Cry-ane" video, which details how they tricked her into believing she had a pen pal named Leo and they later set her up (and filmed her) with a hobo as her homecoming date.
- Establishing Character Moment: Diane's first onscreen appearance is almost unstated, with her coming out behind BoJack during the party, showing her as ''different'' to the rest of Hollywood. The distance and brief talk between her and BoJack show them becoming pretty intimate with each other, with BoJack being able to open up a little. Then we discover that she's Mr. Peanutbutter's girlfriend, highlighting her odd choice of men and becoming the unobtainable for BoJack. Yet, despite hearing BoJack insult Mr. Peanutbutter, she never once calls him out, proving her to be very patient. Plus, she Wrote the Book about Secretariat, BoJack's childhood hero.
- Fish out of Water: Diane hails from Boston, is an acclaimed writer and a quiet person in general who hates being in the spotlight unless necessary, yet stands firm by what she thinks is right and isn't above wanting to have some fun. However, as the show presents and as she finds out, the dog-eats-dog world of Hollywoo doesn't care for those things, thinking nothing of her as an individual, writer or woman, morality she's ill-equipped to face.
- I Just Want to Be Special: Despite her constant arguments that she's happy the way she is, a large part of Diane's Character Arc is her desire to leave a mark in the world in a meaningful way, and her increasing sense that she's wasting her life writing typical celebrity bullshit and settling into a marriage because of a fear of independence instead of chasing after what she truly wants.
- It's for a Book: Diane is hired by Penguin Publishing to help BoJack finish his biography, since he has let the publication slip without presenting anything. As part of it, she starts following him, interviewing him and hanging around his house in order to write him in the most realistic way.
- Named After Someone Famous: While bonding with Kinko, Diane mentions that her name means "my parents used to enjoy watching Cheers".
- Nice Girl: She's never completely mean to anyone and is one of the few, besides Todd, to show any genuine sympathy towards Bojack, although she's more than willing to call him out if needed. Although this can be downplayed when personal issues, ideals and self-importance comes to the front. See Jerk with a Heart of Gold above.
- Outnumbered Sibling: She's the only sister of several brothers and one of the only two females in her family.
- Raised by Dudes: Sure, her mother had a certain part in her upbringing, but Diane's childhood was spent at the service and mercy of her 4 brothers and very old-fashioned dad. As such, their impact on her and her development was pretty much influenced in both good and bad ways: for one, her victimization at their hands has made her a pretty reclusive, quiet person with a desire to make a change in society; on the other side, their manly attitude bordering on Anti-Intellectualism has rubbed on her. She clearly loves reading, books and information precisely for the same reasons they loathe them, yet Pride and Chronic Backstabbing Disorder rear their ugly heads over and over, with her ironically hot-headedness, dressing code bordering on tomboy, uninterested on female behavior proportionately inverse to female ideals and haughty reasoning clearly traits inherited by her in part due to her family, for several reasons.
- Running Gag: Throughout the series, Diane's ringtone is portrayed by different personalities of public radio, such as Ira Glass, Sarah Koenig, and Terry Gross.
- Shrinking Violet: She tries to avoid overstepping boundaries, often struggles to find the correct thing to say, apologizes even through she doesn't need to and often avoids large crowds and parties to not get embarrassed.
- Smart People Wear Glasses: An intellectual Vietnamese-American woman with quite good looks who uses glasses. She's also one of the more level-headed members of the main cast.
- Soapbox Sadie: Despite her generally introverted personality, she'll push hard for worthy causes.
- Took a Level in Cynic: By the end of season 2, it's clear that she has become more jaded about her capability on leaving an impact on the world as she had first assumed.
- Toxic Friend Influence: After staying at BoJack's house for several months after returning from Cordovia feeling like a failure, Diane decides to put some distance between them in Season 3, as she feels they're Too Much Alike and they bring out the worst in each other. (Or rather, he in her.) This is why she ends their friendship for good in the Series Finale. His unspoken expectation that she be this perfect person who could "save him" from himself put so much pressure on her to be responsible for his happiness and wellbeing, then feel like a failure when she inevitably couldn't, was part of why she self-destructed over the series.
- The Unfavorite: She has a lot of hard-drinking Bostonian brothers who do absolutely nothing with their lives, and yet Diane is still the one their mother criticizes the most. It seems to stem from their mother's belief that anything out of Hollywoo is toxic. She's not entirely incorrect about that, but Diane's attempts to improve herself and have her family tell her that they're proud of her is baffling to BoJack since they never give her even the slightest bit of encouragement.
- The Watson: Being a ghostwriter assigned to write his memories, Diane's questions and reactions, as well as commentaries to BoJack's Flashbacks lead to the show portraying an increasingly clear portrait of his persona, as well as multiple neuroses and obstacles, as the two of them eventually get to known each other.
- "Well Done, Daughter!" Girl: Despite denying it earlier, this is her motivation for all the abuse she takes from her family: She knows it's futile, but she wants some recognition from their part for all the things she has done.Diane: The stupid thing is, even now I still just want them to be proud of me and think I did good. Is that really stupid?
- Wet Blanket Wife: A sympathetic, justified example. Diane can be a little pessimistic about Mr. Peanutbutter's plans and promises, but when you are married to a hyperactive, easily distracted and Secretly Selfish Labrador, being cautious is always welcomed.
- White Sheep: She's the only member of her family that is actually well adjusted and responsible. As such, they treat her with mockery and contempt.