Why does The High Queen send Majo Rin to investigate the Wizard World after Yuki runs into Oyajide during Sharp? It doesn't make sense why her majesty would have her right hand attendant do this until you realize that Yuki isThe High Queen in disguise!
Why is the Big Bad able to curse Hana into hating vegetables? Wouldn't that be forbidden magic and therefore cause her to fall into a deep slumber? And then you find out she really is in a deep slumber in the first place from another curse.
Doremi came up with the "Pretty Witchi [Ojamajo's Name]-chi!" right after she first transformed. Majo Rika implied that the phrase had never been heard before given her reaction. Fast forward when Onpu transforms once and we hear her saying "Pretty Witchi Onpu-chi!". In her case, it's justified since Majo Ruka likely told her about it. Fast forward to Motto and we see that Momoko says it too. It can stump people, but then you realize that the girls who made it had done a lot for the Witches by then and likely inspired many other Witches to say it occasionally along with their apprentices (if any). In short: In-UniverseMemetic Mutation!
All Witch Queens were born in a year a millennium started.
Every Witch gets a Fairy, right? So where are the Fairies of the other Witches? Especially the Fairies of those who're already dead?!
In Season 1 Episode 18, Hazuki uses healing magic to heal a bunny she gave to a friend. The bunny's injuries were severe and the only thing stopping Hazuki from suffering the same fate was the Queen of the Witch World using her magic to soften the blow in exchange for Hazuki losing her magic for some time. Since it's been established that healing magic transfers the injuries to the caster and the bunny's injuries were life threatening, where did the rest of the injuries go?
A bit of Fridge Tear Jerker, but during Episode 46 of Dokkan!, the Curse of Majo-Gaeru was eliminated and all of the Witches who've been turned into Witch Frogs were turned back to normal (except Majo Rika). However, it was established that Majo Monroe died as a Witch Frog. Just how many other Witches suffered that same fate?
What if Momoko succeeded in bringing back Majo Monroe? How would her parents react to their daughter being dead?
Whether or not Nozomi could've survived her cancer. Given what her illness was, she really and truly could've lived and become an Ojamajo. But then it hit home: When Doremi and the others granted Nozomi's wish to be a Witch for one night, they mentioned that she may have had some magic of her own which assisted in the final spell of the night. But casting magic like that in the middle of the night when you need rest, even if it was to grant a wish, is not good for someone with any illness. In short, we could be facing a very serious case of Nice Job Breaking It, Hero! when the energy used that night was for casting when it could've gone to her recovery and thus reducing her chances for survival. It is thankful that she died happy, knowing that she had become a Witch for that one occasion, but the implications are there regardless: The Ojamajos could possibly and inadvertently have caused Non-chan's death, and it is entirely possible that they wouldn't find out until much later, if at all.
If magic spheres are used by witches as currency and witch apprentices to cast spells, isn't that literally wasting money?
Momoko's ABC song in Motto episode 7 was cute, but how would she even know a song like that if she lived in America most of her life and could barely speak Japanese? Even with the translating headset, that one doesn't make sense.
According to Ojamajo Doremi 16, the girls all had a lot of credit in the Witch World. At the same time, Majo Rika had gained permission from The High Queen to return to the human world. In that case, couldn't the girls have askedThe High Queen if they could live in the human world AFTER accepting their powers?
Why couldn't the Ojamajos use the same spell they did when Poppu summoned ghosts at the preschool sleepover in the episode where Poppu becomes a witch apprentice (The spell was something among the lines of "Put everyone to sleep"), when they were found out to be witches?
How did Majo Monroe know about the "Tourbillon My Love" cake? Wasn't she born after the cake was first created?