Magical Girl Queenliness Test

A Magical Girl trope. Usually more heavily linked to the Cute Witch, especially travellers from other realms or planets, than other types of magical girls.

Basically the protagonist is a magic user who is a candidate to become Queen back in her home realm/planet/whatever. She has come to Earth as part of a test of character to prove she is queen material, either by making the world a better place with her magic, or by directly competing with a (usually friendly) rival (who often is at least somewhat of a Dark Magical Girl) to accrue some sort of Plot Coupon to prove her worthiness. That or it is just tradition for magical princesses to spend some time on Earth before they can become queen. While doing so she usually lives with some Muggle Foster Parents who may or may not know she is magical.

Not all magical travellers have this plot element, some of them just visit earth out of curiosity and others are sent there to make it a better place or reconnect it with their home realm which may be in jeopardy but don't have the Queen competition element (so this trope doesn't include Princesses who would become queen anyway regardless of if they ever visited the planet e.g. Magical Princess Minky Momo and Sally the Witch who are magical princesses and Earth visitors, but aren't being specifically tested, don't count - Sally does have magical tests, but these are in regards to her magical skills than her queenly aptitude). Note if the Magical Girl in question never leaves her realm but is still competing for Queendom then she probably does count, but visiting Earth is fairly common to this trope.

There may be a Secret Test of Character involved.

Anime and Manga

 * Ultra Maniac has this in the anime but not in the manga, where Nina Sakura merely came to Earth from the Magic Kingdom as a hopeless transfer student. In the anime she is searching for five "Holy Stones" so she can marry the Prince of the Magic Kingdom. She is competing with her childhood friend Maaya, an anime only character.
 * Sugar Sugar Rune Chocolat and Vanilla are competing in order to become Queen of the Magical World by seeing who can steal the most "hearts" from humans.
 * Majokko Meg-chan was both the first magical girl show to introduce a rival, and it was pretty much the Trope Maker for this trope too. Meg-chan is competing with another extra dimensional traveller called Non for the throne. She has a Muggle Foster Family (other than the mother, who is also a witch) and she herself has no concept of family coming from a realm where families don't exist. In the end,
 * Played with rather interestingly in Hana no Ko Lunlun. The titular Cute Witch had to find the MacGuffin (a magical flower) in her travels -- but it was nor for herself but to enable someone else (the Prince of the Flower Star) to legitimately ascend to the throne. On the other hand, the Big Bad Togenishia was a Vain Sorceress from the Flower Star who wanted Lunlun to find the Plot Coupon and then steal it from her so she could be crowned as Queen instead.
 * Petite Princess Yucie never visits Earth but she is a Magical Girl (albeit in a seinen series) competing with other mages for the title of Queen.
 * Hime-chan no Ribon has a variation on this. The titular Magical Girl isn't the princess, but it's her job to test out the magic ribbon Erika, her magic world counterpart, created to prove that Erika is worthy as a princess.
 * This is the premise of the third season of Onegai My Melody, where My Melody and Kuromi are being considered as the new Princess of Mary Land.
 * This drives the plot of Magical Angel Sweet Mint.
 * This trope is the entire plot of Zatch Bell. 100 child demons are sent to earth to fight one another and the last one standing is crowned King of their world.

Film

 * Pan's Labyrinth features easily one of the darkest examples of the trope. Ofelia must go through three dangerous trials to prove to the Faun that her "essence" is still intact, and she is worthy to return to the Underworld as Princess Moanna, all while dodging her sadistic Fascist step-father.
 * Assuming, of course, that all the fairies aren't simply the product of Ofelia's imagination...

Live Action TV

 * Stargate Atlantis has a slight variant on this in the 4th season episode "Harmony" -- the princess doesn't visit Earth, but is required to complete a task and activate an Ancient device to prove her worth as the new Queen.

Tabletop Games

 * The Yu-Gi-Oh! TCG references this trope with the card "Trials of the Princess" which is used to turn either White Magician Pikeru or Ebon Magician Curran into Princess Pikeru or Princess Curran.

Video Games

 * The Angelique series centers around an inverse version of this: the protagonist is competing against a rival to see who will become Queen, but the girl is taken out of her normal life on Earth to become a Queen Candidate.

Anime and Manga

 * Pretty Sammy has a variation, like LunLun before it Pretty Sammy isn't competing to become Queen herself. Instead she is the champion of Tsunami, one of the candidates for Queen. Her rival, Pixy Misa is the champion of a different candidate called Ramia. Pixy Misa sends monsters for Pretty Sammy to fight. Making this more of a Magical Girl Warrior series.
 * Dai Mahou Touge has a princess sent to Earth for a year from a realm called Magical Land, due to it being tradition for Magical Land's Queens. But this magical princess is evil (but still cute!) and causes a lot of destruction, including killing everyone who threatens her even slightly, the opening sequence has her dancing over burning cities and her magical phrase is "Lyrical Tokarev, Kill Them All!".
 * Referenced in Mahou Sensei Negima. When Asakura first witnesses Negi's magic, she briefly wonders if he might be doing a (genderflipped) version of this. She also considers the possibilities of him being a superhero or an alien.
 * Surprisingly, she was partially right; Negi came to Japan to teach as part of a test to become a full mage.
 * "Superhero" does a decent job of describing Negi's role. And