Well, the magic system might be integrated with Japanese folklore. For example, instead of wands, they might use something like Japanese talismans. And Hogwarts could be a Japanese - style castle or temple - like structure, with different houses representing different Japanese clans perhaps.
In this kind of fanfiction scenario, it would be really interesting. Harry might have to adapt to Japanese culture while still having his magical abilities. Maybe he would attend a Japanese wizarding school that has some unique features inspired by Sekirei. For example, the school could have some sort of spirit - like the Sekirei - associated with it in a magical way.
Another difference is in the social structure. Japanese society has its own values and hierarchies, which can be reflected in the fanfiction. So, relationships between characters might be different. In a Japanese - inspired Hogwarts, for example, there could be more respect for elders and a different way of handling conflicts among students, which would be interesting to explore in the fanfiction.
Perhaps he'll meet a mysterious old wizard who lives in a secluded temple in the mountains. This wizard could be a master of ancient Japanese magic and could teach Harry about the spiritual side of magic that is deeply ingrained in Japanese culture. Harry might also meet a group of young Japanese witches who are training to become magical healers. They could share their knowledge of Japanese magical plants and how to use them for healing, which would be very different from the healing methods Harry learned at Hogwarts.
Well, he might go to a Japanese wizarding school. It could be a place where they combine traditional Japanese magic with the spells he already knows. Maybe he'd have to learn to use a magic katana instead of a wand!
Well, he might be really confused at first. Japan has a very different culture from the wizarding world he's used to. He could encounter Japanese magical creatures that are unique to their land. Maybe he'll visit a Japanese wizarding school and be amazed at their different teaching methods and spells.
In such a fanfiction, Harry would grow up in a completely different cultural setting. He might have different friends, perhaps those from traditional Japanese wizarding families. His upbringing could be influenced by Japanese values like respect for elders and harmony with nature. His clothing style might also be a blend of the wizarding robes and traditional Japanese garments. He could also face unique challenges like dealing with Japanese magical creatures that are different from those in the UK.
A really cool fanfiction idea could be that the Deathly Hallows have some connection to ancient Japanese magic. So, Harry and his friends have to travel to Japan to uncover the secrets related to the Hallows and how they interact with Japanese magic.
You can try some popular fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfictions from various fandoms, including Harry Potter, and might have some Japan - related ones.
These fanfictions usually delve into the cultural clashes and adjustments Fem Harry Potter has to make. They might incorporate elements of Japanese folklore and magic, adding an exciting twist to the familiar Harry Potter world.