Kingyo Chuihou

Also known in the United States as Goldfish Warning. Demented 1991-vintage borderline surreal comedy from the production team that created Sailor Moon, but predating that show.

Chitose Fujinomiya is a snobbish young girl, orphaned and impoverished by the death of her father. Thrown out of her exclusive, ritzy private school ("Tokaino Gakuen", a pun which can be read as "Big City High School"), she and her only remaining possession (a strange pink goldfish named "Gyopi") find themselves at Inakano Chugakko (another pun -- "Out in the Country Junior High"). Inakano is not exactly what she's used to -- it's dilapidated and farm animals wander both the grounds and the classrooms. Despite their rough manners, though, the students are good-hearted, and Chitose soon makes several friends (whether she wants them or not), including pink-haired semi-ditz Wapiko, good boy Shu and token delinquent Aoi (who despite their apparent differences all hang out together).

Then her late father's lawyer shows up, seeking to steal Gyopi. Gyopi, it turns out, is an extremely rare and valuable fish, and just about the only thing from the estate of Chitose's father that the lawyer hasn't already plundered. But the school's guard chicken (yes, guard chicken) catches him in the act and raises an alarm. He is caught and in the process drops a key to a safe-deposit box in which Chitose finds her lost inheritance -- billions of yen in stocks, bonds, deeds and other documents.

With the money Chitose could return to Tokaino Gakuen, but instead she chooses to remain at and rebuild Inakano Chugakko. She then installs herself as head of the student council, and tries to "elevate" the school and its student body, while at the same time getting revenge on Tokaino. Most of the subsequent episodes deal with her efforts at sophisticating her classmates, and how her own snobbishness both sabotages her efforts and keeps her from enjoying herself the way her friends do.

This is a strange, high-energy show where the characters spend almost half their time Super-Deformed. Chitose plots and yells at people, there are a lot of random cows and chickens in almost every scene, and the principal of the school has antennae. If you don't expect things to make a lot of sense, but do like off-the-wall, slapstick-style comedy, you'll enjoy this show.

Tropes used in Kingyo Chuihou include:

Absurdly Powerful Student Council: Justified, in this case, as Chitose is student council president and also owns the school.
Bastard Boyfriend: Completely averted, with Chitose showing a surprising degree of Genre Savvy for a character who usually has no sense of self-awareness. Her former love interest, who quickly dumped her when she briefly became poor, discovers she's rich again and wants to get back with her. She's having none of it.
City Mouse
Cool Old Guy: Inakano's principal, complete with antennae.
Corrupt Corporate Executive: Tanakayama, Chitose's former lawyer.
Cross-Popping Veins
The Ditz
Fish Out of Water: Chitose, even after months at Inakano.
- Far more literally, Gyopi, who can fly and apparently breathes air just fine.
Genki Girl: Wapiko takes this trope to the extreme.
Hey, It's That Voice!: Many of the show's actors would go on to have major roles in Sailor Moon. Mika Kanai (Wapiko) was Mimete, Taiki Matsuno (Takapi) was Pegasus, Shino Kakinuma (Takapi's sister Chieko) was Naru, and Keiko Han (Yurika) was both Luna and Queen Beryl. Though it's likely a coincidence, Yurika in her evil moments looks really like a young Queen Beryl.
Joshikousei
Memetic Mutation: Apparently, Gyopi is one in the Doom community of all places!
The Mole
Noblewoman's Laugh
Non-Human Sidekick
The Ojou: Chitose.
Ordinary High School Student
Parental Abandonment
Princess in Rags: Chitose... for about ten minutes in the first episode. She learns nothing from the experience.
Pygmalion Plot: Albeit a doomed enterprise from the start. Chitose tries and fails to "refine" Inakano's students.
Rich Bitch: Chitose, to a degree, but more so her former schoolmates at Tokaino.
The Rival: Yurika to Chitose. Really, Tokaino in its entirety to Chitose.
Slobs Versus Snobs: In part, though the rivalry between Inakano and Tokaino is manufactured almost entirely by Chitose. Inakano's students have little interest in competing with their rich counterparts.
Speech-Impaired Animal: Gyopi, possibly; it's hard to tell when you don't speak the language.
Super-Deformed: Characters spend so long in this mode that the animators developed three distinct levels of super-deformedness for each main character. While many anime will change all of the characters in a scene to super-deformed for a gag moment, this show routinely features interactions between normal-sized characters and super-deformed characters, leading to bizarre situations such as a super-deformed character running between the legs of someone who would usually be the same height as them.
The Sweat Drop
Troubled but Cute
Unsympathetic Comedy Protagonist