Another character could be a rival cook. This person could be from a different magical school in Japan and is competing with Harry in a cooking duel. Each tries to outdo the other with their creative Japanese food creations.
There could be a group of Japanese students who are initially skeptical of Harry but later become his allies. For example, a shy girl who is really good at Japanese magic but lacks confidence. And a tough - looking boy who is actually very kind-hearted and they all form a sort of magical study group together with Harry. There might also be a mischievous Japanese magical creature that befriends Harry and causes some chaos in the school.
Maybe Harry is on a quest in Japan and has to cook Japanese food for a powerful spirit as an offering. He has to learn quickly about the proper preparation and presentation of the food, and along the way, he discovers the cultural significance of Japanese cuisine.
Harry could be the same Harry Potter we know from the books, a brave and kind - hearted wizard. Kara could be a character from another universe, perhaps with superhuman abilities like flying or super strength. Maybe she's an alien like Supergirl Kara, but in this fanfiction, she's in a situation where she needs to be adopted by Harry.
Hermione could be one of the characters to help Harry. She's intelligent and resourceful, so she could provide practical help like finding a good doctor or helping with magic - related pregnancy issues if it's in a magical world. Another could be Hagrid. He has a big heart and could offer emotional support and perhaps a place for Harry to stay if he needs it.
Neville Longbottom could be a main character. He has always had the potential for great things and in a world without Harry, he would be likely to step into the spotlight. He has the courage and the connection to Hogwarts that could make him a central figure in the fight against evil.
The main characters could include the butterfly's kin. For instance, if the butterfly is part of a colony or a family of magical butterflies, they would all be important. They might have different abilities and personalities. There could also be a wise old owl in the butterfly's world that acts as a guide for Harry, teaching him about the new world he's in. And don't forget about the possible presence of a shadowy figure that lurks in the background, representing the unknown danger that Harry has to face.
They could be very traditional and strict pure - blood wizards. Maybe they were part of some ancient magical order and had high expectations for the Potter family. They might be disappointed in how James and Lily Potter deviated from some of the old ways, but be very proud of Harry when they get to know him.
Harry Potter himself would be in the thick of it. He's always in the middle of action at Hogwarts, and a food war is no exception. He might use his skills as a Seeker to quickly gather ingredients or dodge food attacks. Neville Longbottom could be there too. He has a deep knowledge of plants, which could be useful when it comes to identifying edible and useful ingredients in the Hogwarts gardens. Plus, his growth in confidence would make him a valuable team member in the food war.
Maybe some of the Hogwarts professors like Professor Sprout. After all, she's the Herbology teacher. She could give Harry some expert advice on how to grow different kinds of food plants. She might even let him use some special greenhouses or tools in the school for his food - growing projects.
Obviously, Fem Harry would be the main character. There could also be characters inspired by Skyrim, like the Dragonborn or various NPCs that Fem Harry interacts with, such as shopkeepers or guild masters.