Simple. Look at the history of the series. J.K. Rowling wrote it all by herself with no prior source material. So it's not fanfiction.
One can prove it wrong by examining the origin of the story. J.K. Rowling had the idea for Harry Potter herself. She spent years developing the characters, the plot, and the setting. There's no evidence of her using another work as a base for her story. Also, the fact that it has been so widely recognized as an original work in the literary world is further proof that it's not fanfiction.
Well, to prove it, consider the themes. Harry Potter has themes of friendship, courage, and the fight against evil in a very specific context of a hidden magical world within the Muggle world. Peter Pan has themes of childhood, growing up (or not), and the allure of a fantastical place. The settings are also distinct. Hogwarts and its associated locations are very different from Neverland. And the character development in Harry Potter is a long - term process throughout multiple books, while in Peter Pan, the characters are more static in their nature. So, clearly, Harry Potter is not Peter Pan fanfiction.
By examining the characters. In Harry Potter, we have characters like Dumbledore, a wise and powerful wizard, and Snape with his complex backstory. These characters are unique to the Harry Potter world. In Devil Slayer, the characters are designed around the concept of slaying demons. There is no overlap in their character concepts. Moreover, the magic systems are distinct. Harry Potter has spells like 'Expelliarmus' and 'Avada Kedavra', while Devil Slayer has its own set of abilities for its characters to fight demons.
We can prove it by examining the origin. 'Harry Potter' was conceived by J.K. Rowling as her own original idea. There is no pre - existing 'Potter' work that it was based on as fanfiction typically is. Also, the commercial success and widespread acclaim it received are signs of its originality. If it were fanfiction, it would likely face legal and ethical issues in terms of copyright and mass - market distribution. The complex character development in 'Harry Potter' also shows that it's an original work. Each character has a distinct backstory and growth arc that was carefully crafted by the author, not something borrowed from a pre - existing fan - based concept.
Well, first of all, the publication history of 'Harry Potter' shows that it was an original work developed by Rowling. The story is centered around Harry, Hermione, Ron, and their adventures in the wizarding world. 'Genesis Rhapsodos' is from another story. Fanfiction is derivative work, but 'Harry Potter' has no such derivation from 'Genesis Rhapsodos'. We can also look at the cultural impact of 'Harry Potter' which is based on its own independent story, not as fanfiction of something else.
One major difference is the magic system. In Harry Potter, magic is taught in a school, and there are specific spells like 'Expelliarmus' and 'Wingardium Leviosa'. In The Witcher, magic is more of a natural and often dangerous force, and not everyone can use it in the same way. So, it shows they are not related as fanfiction would imply.
Simple. Look at the settings. 'Harry Potter' is mainly set in a magical school, wizarding villages, and other magical places. Tarzan is set in a jungle. Also, the characters are very different. Harry is a wizard, and Tarzan is a jungle - man. So, they're not related in that way.
Well, first of all, the origin. Harry Potter was created by J.K. Rowling based on her own imagination. It has a very British - influenced magical world with things like the Ministry of Magic. In contrast, Arrancar comes from the Japanese manga and anime Bleach. Just the cultural backgrounds are so different. Also, the magic in Harry Potter is more about spells and potions, while in Bleach, it's about spiritual power. So it's obvious Harry Potter is not an Arrancar fanfiction.
By looking at the story's origin. Harry Potter was created by J.K. Rowling as an original work, not based on Grim Reaper fanfiction. The characters and their relationships are unique to the Harry Potter universe.
We can prove it by looking at the basic elements of each. Harry Potter has magic wands, spells like 'Expelliarmus' and 'Lumos', and magical creatures like hippogriffs and house - elves. Green Lantern has power rings, constructs made of green energy, and villains from outer space. The settings are also different, one is in a magical Britain and the other in a vast DC Comics universe. So clearly, Harry Potter is not a Green Lantern fanfiction.
We can prove it by comparing the settings. Harry Potter is set in a magical, somewhat medieval - inspired world with castles and forests. The magic is an integral part of the daily life there. Space Marine fanfiction is set in a far - flung future in space, with high - tech weaponry and space - faring civilizations. The themes are also different. Harry Potter focuses on friendship, good vs evil in a magical context, while Space Marine fanfiction is more about combat and survival in a space - based military scenario.