Kokubu Karin (Kassie Carlen in English dub) is an ordinary middle school student, much in the mold of your standard Magical Girl heroine, she is constantly Late for School and has a crush on the school soccer captain, Mizuno Kouichi. On her way to school one day, Karin finds an injured yellow piglet which turns out to not actually be injured, merely hungry, and he steals her apple. He stows away in her school bag, and causes havoc for her throughout the day until she finds a compact on her way home.
A pink pig's snout flies out and attaches itself to her face. This freaks Karin out, but she's also taken by surprise when she finds the piglet (Tonrariaano) can talk, and is an alien from the planet Ringo (that's Japanese for apple, nothing to do with The Beatles). He tells her to say, "BA BI BU BE BOorin!" She does, thinking this will remove the snout, but instead she transforms (via Transformation Sequence) completely into a caped pig! This form is called Justice Buurin (more often just Buurin). Suffice to say, poor Karin is not happy about this, on the upside though she now has an arsenal of Stock Super Powers which she does find pretty cool. After saving a young boy from a house fire she returns home and Tonrariaano (or Ton-chan) tells her how to turn back, she is told she can become any heroine she wants if she collects 108 pearls for her good deeds. She agrees but if anyone finds out about her Secret Identity she'll be stuck as Buurin for life!
Has several other language dubs, including an English one (Super Pig) which aired redubbed to Spanish in Latin America (Super Cerdita, where it was a huge hit), and a couple of episodes of which aired on Fox Kids UK's anime weekend way back in the early 2000s.
Contains examples of:
- 108: The number of pearls Karin needs to get a better superhero identity.
- Affectionate Parody: Of the Magical Girl/Magical Girl Warrior genre.
- Alien Animals: Ton-chan as well as his father are apparently a race of alien pigs from another planet that's shaped and colored like a red apple.
- All Love Is Unrequited: Local Rich Boy Takuma has a crush on Karin. The Alpha Bitch Kyoko crushes on Takuma. Karin crushes on Mizuno. Mizuno crushes on... Buurin.
- Alpha Bitch: Kyoko Kuroha, the class president (though more just rich and powerful than popular)
- Alternative Foreign Theme Song: The English version (and any other version based on it) uses a different theme song.
- Animal Superheroes: well, her civilian form is human but...
- Balloon Belly: Karin in Episode 4.
- Broken Aesop: In one episode of Ai to Yuuki no Pig Girl Tonde Buurin Karin once got a demo of the Magical Girl form she wished for to try for one day, however she failed solving a dangerous situation making her deliberately become Buurin again to do that. While this was probably meant as a "maybe what you already have is better than you think" but is broken since her demo did not possess any super powers aside flight making it pretty much useless as a super form.
- Same thing happens in the final story arc, but Up to Eleven. The aesop here would be that Karin could be a great heroine, even without powers. Problem is, while a normal person can do a lot of good and heroic deeds, it pales in comparison to the good a person could do with those powers; especially considering the kind of crisis that Buurin has to face through the series.
- By the Power of Grayskull!: "BA BI BU BE BOorin!": It's a nonsense spell, based on Japanese vowel order AIUEO rather than the Latin AEIOU.
- The Fool: Karin.
- Gratuitous English: Keiko often says singular words in English, with a bit too much emphasis on pronouncing them, which makes her sound like she has an accent.
- Interspecies Romance: Kouichi Mizuno, who Karin has a crush on, has a crush on Buurin, despite her being a sentient pig in that form. Ton-chan develops a brief crush on Karin's best friend Masami at one point too.
- Late for School
- Loves My Alter Ego: As mentioned above. Despite that alter ego being a pig. When Kouichi finds out that Karin is Buurin, he is upset at this first, but accepts the fact.
- Meganekko: Masami, Karin's best friend.
- Opaque Nerd Glasses: Worn by nerdy classmate Jimmy Matsumoto.
- Ordinary High-School Student: Middle school, close enough.
- Secret Identity: If anyone figures it out, she's stuck as a pig for life!
- Secret Keeper: Kouichi, Masami, Kashiwagi, Kaoru, Jimmy, Kyoko, and Takuma ended up finding out that Karin is Buurin in the second to the last episode.
- Shapeshifter Mode Lock: Karin will be stuck as a pig for life if anyone finds out that she is Buurin which happens when her classmates find out her Secret Identity.
- Shrinking Violet: Sweet pink-haired Kaoru.
- Stealth Pun: The pig superhero is collecting pearls...pearls before swine.
- Stock Super Powers: Super Strength, flight, some other more specific but not especially magical girly powers
- Superhero: Buurin is part Superman pastiche as well as Magical Girl Warrior pastiche
- Talking Animal: Ton-chan, Buurin herself.
- Transformation Sequence: One of the oddest in anime.
- Transformation Trinket: The pink compact that carries the pig's snout and communicates to Ton-Chan's father, the King.
- Unexplained Recovery: Buurin after transforming back as Karin with the 108 pearls.
- Word Salad Title