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.
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!
Perhaps Harry is on a sort of exchange program. He has to adapt to the Japanese wizarding school system. He makes new friends who introduce him to Japanese culture. They go on adventures together in Japan's beautiful and sometimes spooky landscapes, like exploring an old haunted shrine that has a magical secret within. Harry's presence also brings a new perspective to the Japanese wizards and witches about the outside magical world.
He could meet a Japanese witch or wizard who becomes his best friend. This person could teach him all about Japanese magical traditions and how to navigate the Japanese wizarding world. For example, they might show him how to use a Japanese - style magic wand.
In a Sekirei fanfiction set in Japan, Harry Potter's story would take on a whole new direction. He would be exposed to Japanese mythology and magic which could be very different from what he learned at Hogwarts. The Sekirei themselves might have powers that are either complementary or in conflict with his own magic. His relationships with other characters would also be different. Instead of the typical Hogwarts friendships, he might form bonds with Japanese wizards or Sekirei based on different values and goals.
Maybe Harry meets a group of magical creatures' protectors in Japan. They are dedicated to protecting the unique magical creatures in Japan, and Harry joins them in their adventures, learning a great deal about Japanese magical fauna along the way.
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.
Well, it could be about Harry going to Japan for a magical exchange program. Maybe he meets new wizards there, discovers unique Japanese magical creatures, and learns different types of magic that are specific to Japan.
Hermione might visit Harry. She would probably be worried about him living alone and bring him some books she thought he'd like or some new potions she'd been working on.