Some of the survivors of the war who Harry has saved or befriended. These people might feel a deep sense of gratitude towards Harry and include him in their family. They could be other witches and wizards who lost their own families in the war but find a new one with Harry.
There could be new characters introduced. Maybe a magical creature that Harry befriends during his post - war adventures. This creature and its family could adopt Harry into their fold, and Harry would become part of their unique family structure in the wizarding world.
His friends like Ron and Hermione could be part of it. They've been through so much together, and after the war, they might decide to live close to each other and consider each other family. They could raise their children together and share holidays as one big family.
Maybe Harry discovers long - lost relatives who come forward after the war. For example, a distant cousin could show up and welcome him into their family. They might share stories about his parents that he never knew.
Perhaps a family of magical scholars. They would expose Harry to all kinds of ancient magic texts and theories. This would make Harry not only a better wizard in terms of practical magic but also in understanding the deeper roots of magic. They could be the ones to finally unlock the full potential of Harry's magic, which was stunted by his difficult upbringing at the Dursleys.
There could be new characters introduced as part of Naruto's family. For instance, a young girl from a foreign land who Naruto saves during a mission. She could have no family left and Naruto decides to take her in. She could bring a fresh perspective to Konoha and to Naruto's life, with her different cultural background and unique abilities.
It could be an old pure - blood family that has been in the background in the original series. Maybe the Blacks who have some complex family dynamics already and taking in Harry could add a whole new layer of drama.
One popular new character could be a young witch from a newly introduced family who has an extraordinary gift for potion - making. She might befriend Harry and help him with some difficult potions in his later years at Hogwarts. Another could be a wizard from a family that has a long - standing feud with an existing family in the wizarding world. His presence could stir up old rivalries and create new story arcs.
It could be a family of pure - blood wizards who have been observing Harry's situation from afar and decide to take him in. They might see his potential and want to groom him into a great wizard.
Perhaps Harry meets magical creatures that are rarely seen by wizards. Since he is out exploring after the war, he might stumble upon a group of centaurs who have their own unique wisdom about magic and the future. He could also encounter veelas, and through his interactions with them, learn more about the different cultures within the magical world. There's also a chance he meets other young wizards who are on their own adventures, and they form a sort of traveling group together.
It could be an older relative who was thought to be dead but actually has been living in seclusion, waiting for the right time to teach Harry about their family magic. This relative might have a vast knowledge of the family's magical traditions and spells.
Some former Death Eaters who escaped justice could be the main antagonists. They might be plotting to bring back Voldemort's ideology in a more covert way. Another possibility could be new dark wizards who emerge, seeing the post - war chaos as an opportunity to gain power.
The Grangers. Hermione's parents are Muggles, but if they were made aware of the wizarding world early on, they could adopt Harry. He'd have a stable, loving home environment and would also be exposed to Muggle knowledge, which could be really useful in his magical studies. For example, scientific methods could be applied to understanding some aspects of magic better.