Obviously, Harry is one of the main characters. His family members could include his parents, if they are alive in the fanfic's universe, or his siblings perhaps. There might also be his significant other, if he has one in the story.
In this fanfic, Harry is central. His family could be a diverse group. It could include his uncles, aunts, and cousins. Maybe there's a young nephew or niece that he's especially excited to bring along to the seats. They all add to the family dynamic and the story could explore their relationships as they sit together.
Maybe Harry shows his family around the special seats, sharing stories about the place. For example, he could tell them about the history of the seats in the stadium or theater, if it's that kind of setting.
Hermione would be a very likely character to help. She's smart and resourceful, and she would use her extensive knowledge of magic to come up with a plan for Harry's escape. Another could be Hagrid. He has a big heart and he's always been fond of Harry. He could provide a means of transportation, like his flying motorcycle or a secret passage he knows of. Also, Sirius Black might be involved. He's Harry's godfather and he would do anything to protect Harry from his family, so he could be a key figure in getting Harry out of that situation.
Most likely, Harry Potter is the central character in 'harry claims his seats fanfiction'. But depending on the direction of the story, it could also feature characters like Draco Malfoy if he is trying to oppose Harry's claim on the seats. Additionally, teachers at Hogwarts such as Professor McGonagall might make an appearance if the seat - claiming incident occurs within the school premises and she has to mediate or enforce rules.
Hermione would definitely be one of his top allies. With her intelligence and knowledge of the wizarding laws, she could help Harry in making important decisions regarding Ministry policies. Ron would also be there, providing his loyalty and courage in times of trouble.
Obviously Naruto would be one of the main characters as the title implies that he is the one being broken by his family. His family members, whether it's his father Minato, mother Kushina, or other relatives in the Uzumaki clan, would also be main characters as they are the ones causing Naruto's distress.
Obviously, Harry would be the main character. He is the one taking control of his life. Hermione and Ron would most likely be important characters too as they are Harry's closest friends and would be involved in his journey. Dumbledore could also play a role, perhaps as a mentor figure that Harry starts to question and break away from as he takes more control.
Obviously, Harry Potter himself is the main character as the whole concept is about him reliving his life. His friends like Ron Weasley and Hermione Granger are also likely to be main characters as they are an important part of Harry's life in the original story and will surely play a role in this new scenario.
Voldemort would still be a crucial character. Since Harry is redoing his life, he might try to defeat Voldemort in a more strategic and less dangerous way. Other characters like the Weasley family, who were always there for Harry, would be involved too. They could be part of Harry's new support system in his redone life.
In this fanfic, Harry is the main character. However, we could also expect to see Dumbledore making an appearance. Dumbledore has always been a guiding figure for Harry, and in a story about Harry showing his power, Dumbledore might offer some wisdom or crucial information. Neville could also be a key character. He has his own growth in the original series, and in this fanfic, he could be inspired by Harry's power and contribute to the overall plot in some way.
Harry is the main one as it's his faked death. Hermione, with her sharp mind, would be a mainstay in the story. Ron, with his loyalty and bravery, would be right there. Neville could also be a main character. He has grown a lot throughout the series and could be involved in the events surrounding Harry's faked death, perhaps even being one of the first to suspect something fishy. And then there's Ginny. As Harry's love interest, she would be deeply affected by his faked death and would be a central figure in the emotional turmoil of the story.