FLCLlge AU (you can tell I put a lot of effort into that title)

Julia Raharu, often referred to by her middle name Jinyu, is an accomplished lawyer working for the legal firm Ikari and Kiryuin, Attorneys at Law who owns a Bel-Air passed down to her from her Italian father, frequently goes out for coffee with her friend and boss's daughter Satsuki Kiryuin, is a card-carrying member of Silverman Gym, and lives in a modest apartment close to her old alma mater of Tsurumaki University.

Coincidentally, that's where Jinyu's rambunctious, mischievous, neurodivergent, and sassy younger sister Haruha Raharu, or her stage name Haruko Haruhara as she prefers to be called, is currently attending, and now Jinyu is forced to house her little sis after Haruko got kicked out of her dorm room by her roommate Nonon Jakuzure for being a nuisance. The last time the two saw each other was when Jinyu graduated high school and moved to Tsurumaki University to study law, so it'll take a while for the two to get used to living together as sisters again. But deep down, beneath her middling empathy and penchant for trouble, Haruko desires for someone to be proud of her, as the girls' father believed that her destructiveness is only wasting her potential.

Also present is Tasuku Nandaba, the oafish but kindhearted leader of the university baseball team that Haruko joins, Adam Smith, an old money upperclassman that Haruko develops a crush on (and basically this universe's equivalent of Atomsk), Tasuku's precocious younger brother Naoto who Haruko becomes a big sister to, and other characters from FLCL.

Other anime referenced include:

Kill la Kill: Ragyo Kiryuin runs Ikari and Kiryuin with Gendo Ikari, her oldest daughter Satsuki Kiryuin is groomed to eventually take over the firm alongside Gendo's son Shinji, Satsuki also happens to be friends with Jinyu as the two go out for coffee and yoga every week on Tuesdays and Thursdays, Nonon Jakuzure is head cheerleader and Haruko's former roommate, Ryuko is a member of a study group Jinyu makes Haruko join to keep her grades up. The two become friends and form a band called The Shooting Star Riders.
Neon Genesis Evangelion: Gendo Ikari runs Ikari and Kiryuin with Ragyo Kiryuin, his son Shinji is being set up to take over the firm alongside Satsuki, Asuka Langley Soryu is a member of Haruko's study group and later becomes one of the founding members of The Shooting Star Riders.
Gurren Lagann: Kamina Gurren is the passionate leader of the university's robotics club alongside his younger brother Simon Gurren and their friend Yoko Littner, Rossiu Adai works alongside Jinyu and Satsuki at Ikari and Kiryuin, Kittan is a member of Haruko's study group and a founding member of The Shooting Star Riders.
Little Witch Academia: Akko Kagari runs the DND club themed around her favorite book series Shiny Chariot du Nord, Diana Cavendish is a second generation student of Tsurumaki after her mother and friends with Nonon.
Brand New Animal: Michiru Kagemori is captain of the basketball team and Nazuna Hiwatashi is her personal cheerleader, Shirou Ogami serves as a history teacher at Tsurumaki, Barbara Rose is the dean of Tsurumaki.
How Heavy are the Dumbbells You Lift?: Jinyu and Satsuki are members of Silverman Gym, where they also take Haruko and Ryuko with them, Akemi Soryuin is a member of the student council and good friends with Milly Ashford.
One Piece: Brook is a fun-loving music teacher that Haruko grows a friendship with, Nico Robin is a campus therapist, Jinbe is a retired Olympic martial artist turned fitness doctor, Franky is a local mechanic who Haruko starts working for, and the other Straw Hat Pirates are basically the Hungry Days ads.
Jojo's Bizarre Adventure: Josuke Higashikata is a member of Haruko's study group, Jotaro Kujo is a biology professor specializing in marine life, Rohan Kishibe publishes Haruko's favorite manga Pink Dark Boy.
Sailor Moon: Usagi Tsukino is a member of Haruko's study group and quickly develops a friendship with Asuka of all girls, Ami Mizuno and Minako Aino are members of the student council, Makoto Kino once dated Kittan, Rei Hino is a member of the archery club.
Code Geass: The student council of Ashford Academy is the student council of Tsurumaki University here with a few additions from the other shows listed here, Kallen Kozuki is a member of the cheerleading team.
Keijo: The elite class of Setouchi Academy are now the girls' swim team and friendly rivals with the boys' team, aka the boys from Free.
Dragon Ball: All the Z Fighters have long since graduated from Tsurumaki Academy. Goku is now a martial arts teacher, Vegeta has taken over his father's company Saiyan Inc. and entered a partnership with Capsule Corp, Piccolo is a former violent tough guy turned babysitter, Krillin has settled down with his crush Lazuli to start a family and became a police officer, Yamcha is a moderately successful baseball player, Tien Shinhan and his little friend Chiaotzu travel the world together, and Yajirobe runs a local coffee shop called Bean Daddy's, Frederick Coleman (aka Frieza) runs Saiyan Inc's chief rival and former business partner Coleman Industries, having inherited the position from his father Kingsley Coleman (aka King Cold).
My Hero Academia: Bakugo was forced to join the study group because his fellow students were tired of his bullying and attitude problems, Izuku is an aspiring comic book artist who credits his favorite superhero All Might as his inspiration for drawing.
Baccano: Issac and Miria are the local theater kids. Come on, look at those two and tell me they don't radiate theater kid energy!
Soul Eater: Maka and Soul are members of Haruko's study group, Black Star is a total weeb who wanted to become a ninja after watching one anime too many (yes, I get the irony) and it's up to Tsubaki to keep him down to earth; so same dynamic as always, Death the Kid is an upperclassman whose father was a student of Tsurumaki before him and his brother Asura, who is currently off working for the military, Crona lives with their mother Medusa, who works as a campus nurse. However, they'd much rather prefer spending time with Maka and Soul due to Medusa's emotional abuse.

And potentially more that I can't list right now!