Karin Kokubu rescues a yellow piglet on her way to school. The piglet turns out to be the prince of an alien planet, though, and turns her into the super-pig Buurin- but she'd rather be any other kind of hero.
Karin's school is having an important soccer match with a rival school, one known for their unfair tricks. Koichi, the star player of her school's team, is going to be the victim of these tricks unless Buurin does something about it.
Karin and her best friend Masami have a falling-out during tennis practice. Having a hard time making up, Karin decides to use Buurin to repair their relationship.
A local park is hosting a female pro-wrestling tournament. Among the wrestlers is an amateur, Buutan, who dresses up like Buurin to fight.
Karin's school's athletic meet is hosting a very special event: a tug-of-war match where all of the first-year students compete with Buurin. Koichi is having trouble organizing the event, though.
On a history field trip, Karin finds an ancient clay figure that looks a lot like Buurin. It leads her to some ruins that give some insight into Buurin's history.
A real bank robber interrupts a live show starring Cutey Chao, Karin's favorite heroine. Buurin must stop him quickly.
Karin has been eating a lot lately, but after a comment from Koichi she decides to go on a diet. She goes too far, though, and gets weaker and weaker- this soon starts affecting Buurin's performance as well.
The race circuit that Keiko Kuroha's family owns is hosting a solar car race. Karin and some of her friends enter a Buurin-shaped car in the race, driven by Ms. Tateshi. When the weather takes a turn for the worse, the situation becomes tense.
Shinichiro Kokobu, editor-in-chief of the Akebono Times (and Karin's father), is on the hunt for a big scoop. He has a new target that he's doing some investigative journalism on- Buurin!
The school's cultural festival includes a 'best couple' contest. Lured in by the promise of a romantic meal for the winning couple, Karin tries to win with Koichi.
Kashiwagi has been really into the supernatural lately, and things are dialed up a notch when a series of coincidences leads him to believe that he has supernatural powers of his own.
As Karin prepares for a big test, she finds out that Ton has a test as well. If Buurin doesn't collect 50 pearls by the deadline, Ton won't be able to become king of Buuringo.
Koichi's making a movie, and he and the others have a perfect pick for the lead actress: Buurin!
Kaoru, disheartened by littering citizens who won't change their ways, decides to take the task of picking up garbage into her own hands. Buurin ends up helping her.
Karin is looking forward to giving Koichi a gift at a Christmas party. He says he can't come, though. Karin is suspicious- he says the reason is that he has a date with Buurin!
Karin comes across an opportunity to see if her future is with Koichi.
There's a big New Years' party at Karin's place! All seems well, but Ton is shut in Karin's room, missing his home planet.
Karin and Koichi get to go (with the rest of their class) to a ski camp. Mr. Arashiyama seems nervous and soon enough Karin finds out he wants to profess his love to Ms. Tateshi.
There's a cool plant in the school (and it's named after Keiko). Trouble arises when the plant grows out of control and Buurin must defeat it.
Karin faces complicated feelings towards Koichi and wonders who he likes.
Ton is in love, and not with someone back on his home planet, either.
It's valentines' day, and. Buurin is helping a local sweets shop to deliver chocolates around town. As orders pile up, she worries she won't even have time to give chocolate to Koichi before the day is over.
Karin's father waits for a natural phenomenon to occur.
Karin has to choose a doll for Girl's day. She's conflicted about which to choose, though.
Buurin and tennis intersect.
Buurin needs to recharge, but has to rescue a puppy and stays transformed for a bit too long, then faces the consequences.
Karin's younger brother has a girlfriend, Hitomi. All is fine until Karin finds out Hitomi has a familiar older brother, one who stood against Koichi's soccer team a while back...
Keiko funds a class trip to Hawaii.
A rumor concerning Buurin is spreading in Hawaii.
Nobody seems to want to run for student council president this year... until Keiko Kuroha steps up to the challenge and throws the entire school into election spirit.
Jimmy Matsumoto has a turbulent history with the annual cherry trees.
The cold is going through town again, and this time Karin (and by extension, Buurin) gets it. It begins to interfere with Buurin's superheroine activities.
Koichi's soccer team faces a big game, but there's some conflict between the players. Mr. Arashiyama says that carp streamers could bring them back together, though.
Two ninjas working for Takuma's family kidnap Karin and take her to Kyoto, where her friends shortly follow. Takuma believes that Karin is in love with him.
Karin gets to help out with rice planting, but it seems tough.
Koichi has written a love letter to Buurin. Karin, determined to make Koichi fall in love with her as herself instead, tries to prevent Buurin and Koichi from ever meeting again.
Jimmy sees Buuringo in the sky and, while trying to investigate, falls into another dimension, creating a series of strange circumstances.
Everywhere Buurin appears, one strange mark can be found. Karin and Ton head to Kyoto in order to investigate the connection between the mark and the Mushanokoji family.
Kashiwagi's grandmother had the chance to become Buurin as well a long time ago.
Jimmy's investigations reach their end and he has a theory: Karin and Buurin are the same person! Karin must convince him that he's wrong, somehow.
Just as Jimmy is about to confirm his theory, another Buurin appears! This new Buurin is fast, strong, and smart- no one seems to know who she is, and to prove herself as the one real Buurin, the original and the impostor have a showdown.
Karin and friends spend a night in the gym basement. Mr. Arashiyama and Karin both have something to hide, so they fake supernatural happenings.
Keiko Kuroha has found a strange compact. As it turns out, it's the very same compact that Karin uses to transform into Buurin!
Karin finally gets the chance to (temporarily) transform into Cutey Chao! In a strange twist of fate, though, Buurin is needed, and so she has to transform back.
Ton and Karin might have to break up their friendship as Karin moves in on her goal of 108 pearls.
Keiko is having a dinner party at her massive, luxurious mansion. It turns out, though, that her parents only come home once a year.
An entrance in a basement leads to another world.
Monsters from Keiko's mansion have broken into the outside world, and they're attacking the school. Karin can't find time to transform into Buurin and fears she'll have to do it in front of the others, locking her into Buurin form forever.
Karin decides to reveal she's Buurin and transform to save the city, but doing this will mean she can never transform back into Karin.
Apparently there need to be 7 Buurins to use the 7 talismans... but there's just one. Karin needs the strength of all of her friends to save the world.
