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 travelers have this plot element - some of them just visit earth out of curiosity (e.g. Mahou Tsukai Chappy), some arrive by accident (e.g. Mahou Shojo Lalabel) 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, Sally the Witch and Mahou no Mako-chan 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 rather 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.
- 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 traveler 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, they BOTH fail the test and pretty much end up right back where they started.
- Played with rather interestingly in Hana No Ko Lun Lun. The title Cute Witch had to find the MacGuffin (a magical flower known as "the Seven Colors Flower") in her travels — but it was not 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. Lunlun succeeds, Togenishia is defeated... and it turns out that the Prince was Lunlun's Mysterious Protector, whom she's in love with. He steps out of the succession line, gives the Flower to his younger brother who's crowned in his place, and marries Lunlun to live on Earth with her.
- 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. In the end, Nina wins, but learns that Maaya loves the prince, and gives her the stones so that SHE can become the princess.
- 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. The winner changes depending on the media - in the manga, Vanilla becomes queen, but in the anime, Chocolat does.
- 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. In a dark twist on the trope, any candidate NOT chosen by the Eternal Tiara will be erased from existence...but if it ISN'T accepted, then the world will be destroyed.
- Himechan 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.
- Onegai My Melody: The third season, Sukkiri, is about My Melody and Kuromi's race to become the new Princess of Mari Land. Each has to collect the scattered Black Notes and turn them into gems for their crown.
- This drives the plot of Magical Angel Sweet Mint - Mint is sent to the world of humans to try to preserve people's hopes and dreams, and to prove that she has the qualities necessary to be a wise ruler.
- 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.
- Hana undergoes this in the last season of Ojamajo Doremi to earn her right to be heir to the Witch World's throne again. Though it should be noted that every witch in training has to go through the exams she did.
- Played with in Yadamon - Yadamon is banished to Earth by her mother the Queen in the hopes that it will help her mature more, and thereby, become a better princess and future queen.
- Oku-sama wa Mahou Shoujo implies that this is how the managers are chosen.
- Lady Jewelpet plays with the trope - while Momona and the other Petit Ladies are all competing for the title of Lady Jewel, only their Mentors are capable of using magic.
- In Princess Comet, Comet is sent to Earth to find the runaway prince of Tambourine Star so that she can marry him. Meteor tags along so that she can find and marry him first.
- The heroes of Mahou X Shounen X Days!!!!! are magical boys who have to perform good deeds in order to become the next King of the Land of Magic.
- Gender-Inverted Trope in Cute High Earth Defense Club Happy Kiss! - Princes Karls and Furaunui travelled to Earth to discover what it means to be a king, and are using their chosen knights in order to prove themselves worthy of the throne.
- Gender flipped in Return to Labyrinth where Toby has to face an ordeal of locating the Labyrinth's consciousness in order to gain control of it. The Labyrinth would have been destroyed if he'd failed.
- While it is never actually the case Queen Hippolyta has been accused of sending her daughter Princess Diana out into the world as Wonder Woman due to favoritism and as a test of her morals and abilities outside of Themyscira on a handful of occasions by the more antagonistic of the Amazons who participated in the contest to see which Amazon would be the one to leave as champion.
- Pan's Labyrinth features easily one of the darkest examples of the trope. A girl named Ofelia, who lives in the times of the Spanish Civil War, 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. In the end, she's shot to death by said stepfather - but, happily, death turns out to be a requirement of being a Princess of the Underworld. Word of God says that the whole deal truly happened in story, and the Underworld and the Faun weren't simply the product of Ofelia's imagination as she tried to cope with her terrible life and later her own death.
- The plot of Thor involves Thor being sent to Midgard when it becomes obvious that he is not worthy of being the next King of Asgard, only regaining his full powers and being allowed to return after he proves himself worthy through heroism and self-sacrifice. Essentially, his exile to Midgard is a Magical Boy Kingliness Test.
- According to the Tsukiuta anime, all members of the female units are candidates for ruler of the moon, and have to undergo training and prove themselves in order to be picked. They make base on the moon, but can easily travel to Earth.
- Lumi of Vocaloid is a jellyfish shrine maiden who is set to become the Goddess of Shinkei, a land on the seabed of Kamakura. In order to be considered worthy, she has come to Earth to transform 1,000 of humanitys "seeds of anguish" into "seeds of hope".
- The Yu-Gi-Oh! TCG references this trope with the card "Trial of the Princesses" which is used to turn either White Magician Pikeru or Ebon Magician Curran into Princess Pikeru or Princess Curran.
- All the Solar Exalted go through this at the moment they take the Second Breath: they must accomplish some incredible feat of inhuman prowess which proves their superiority and worthiness to a Solar Exaltation which grants supernatural perfection in whatever they do. Those who die in the attempt often become Abyssal Exalted, while those who fail or chicken out become Infernal Exalted.
- The Angélique 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.
- Long Live the Queen: The Player Character is a princess who needs to learn the skills required to become queen (due to her mother having died), and possesses capacity for becoming a Lumen (the setting's equivalent of a magical girl). However, the skills required tend to be finance, foreign affairs, and the like, learning magical skills is optional (though useful), and the main test is surviving to coronation in the Deadly Decadent Court.
- If you complete the Hard Mode in Panel de Pon, it's revealed by the goddess Cordelia (Lip's mother) that the events of the entire game were a test to see if Lip had the strength to become the new Queen of the fairies. If you complete it without continues, Lip passes the test; if you used a continue, Lip says she's not strong enough to be queen.
- The Ha'yli'tet'h of Atomic Laundromat - the one undergoing it is cast out of the empire, and must prove themselves worthy to lead, or never return. They are teleported to a planet of their choosing outside of the empire, and get to leave with the clothes on their back, rations for a week and an object (either a weapon or something useless) drawn at random from a ceremonial container.
- The third season finale of My Little Pony: Friendship Is Magic reveals that the entire series up to that point has been a test for Twilight Sparkle, without her knowledge. Her immediate visit to the High School A.U. of My Little Pony: Equestria Girls includes her defending the locals from a rival claimant to her position and power.
- Some version of this is clearly in play in "The Beginning of Rainbowland" (an origin story for Rainbow Brite), where Rainbow — named Wisp — comes to a ruined world on a quest to save it. Initially she has no powers at all, and she becomes ruler over the new world rather than return to her homeland.
- Pretty Sammy has a variation, like LunLun before her 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, thus 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. And it turns out that his mother is a princess, meaning that he actually fits both the "royalty" and "test" criteria for this trope, even if the two things are unrelated.
- "Superhero" does a decent job of describing Negi's role. And his mother and father live (lived?) on Mars, so he's technically an alien.
- Parodied in the final episode of Ninin Ga Shinobuden - in the parody, Shinobu possesses the ability to transform into a Magical Girl Warrior, and is a candidate to become the next Queen of the Magical Land - upon passing, she marries the magical prince Onsokumaru.
- Discussed in Majokko Tsukune-chan - the Mayor is shocked to discover that this trope (as well as Wizarding School and Magic Land) is Truth in Television.
- In Star vs. the Forces of Evil, Star Butterfly is a princess of a magical kingdom in another dimension who's sent to live on Earth...not to pass any kind of test, but because she clearly can't handle the powers of the Magic Wand she inherited from her parents, having almost destroyed the kingdom with it. The thinly-veiled implication is that sending her to Earth is so that any collateral damage she causes while learning to use magic without destroying things will be on a different planet from her kingdom, so that her parents won't have to care about it.