Ron and Hermione would surely be important supporting characters. They are Harry and Ginny's closest friends. Ron could be there for the comic relief and also to offer his practical wizarding skills. Hermione would use her vast knowledge to help Harry and Ginny in any situation, like when they need to research a strange magical occurrence in the post - war wizarding world.
The Weasley family as a whole would play a big part. Molly Weasley would be the doting mother - in - law, always cooking up a storm and giving advice. Arthur Weasley would be excited to learn about any new magical discoveries Harry and Ginny make during their post - war adventures. And the other Weasley siblings would be around for family gatherings and celebrations, adding to the warmth and family dynamic of the story.
The main characters are Harry and Ginny for sure. But it's also possible that some of the villains they faced in life, in a reformed state, could be part of the story. For example, Draco Malfoy could be there, having had a change of heart in the afterlife. This would add an interesting dynamic to the story as they all interact in this new realm.
Luna could be a great supporting character. She might offer her unique perspective and be very supportive of Ginny. Also, Harry, being Ginny's brother, could play an important role. He could be protective at first but then come to accept the situation. Neville might also be there, perhaps helping out with practical things like gardening to provide fresh produce for Ginny during her pregnancy.
Luna Lovegood could be a great supporting character. Her unique perspective on magic and life would add an interesting flavor. Hagrid, of course, would be there, still taking care of the magical creatures at Hogwarts. He could provide a place for Ron and Hermione to relax and get away from the pressures of their new post - war lives. And then there are the younger students at Hogwarts who look up to them. They could be a source of inspiration for Ron and Hermione to make the wizarding world better.
Another character that could be significant is Neville. Since he also played a crucial role in the war, he might be part of the story. Maybe he and Harry work together on some initiatives in Hogwarts or in the wizarding community at large, and Ginny is there to support them, making Neville an important part of the overall narrative.
Obviously, Harry and Ginny are the main characters. Their kids would be important characters too. For example, James, Albus, and Lily. Then there could be their friends like Ron and Hermione, who might be the godparents or just good friends who are always around to give advice or help out.
The two of them could also interact with the Ministry of Magic officials. Harry, being a hero of the war, would have a certain influence. He might try to push for reforms in the Ministry, and Daphne could support him. They would have to deal with bureaucrats who may not be as eager for change, like some of the old - guard pure - bloods who still hold positions of power in the Ministry.
Luna Lovegood could play a supporting role. She might be in Hogsmeade looking for some strange and wonderful creatures that she's heard about. She could then join Harry and Ginny on their little excursions, sharing her unique insights and knowledge. Fred and George Weasley could also be involved. They might be testing out their new products in their Hogsmeade shop, and Harry and Ginny get to be the first customers or guinea pigs for their latest magical inventions.
Harry could become an Auror, as he's always been good at fighting dark forces. Ginny, on the other hand, might continue her career in Quidditch. They would support each other's choices. Harry would cheer for Ginny at her matches, and Ginny would be proud of Harry for his work in keeping the wizarding world safe.
Sakura could be a likely supporting character. She might offer Hinata some advice on married life, as she has been through a lot in her own life. Shikamaru could also be there, perhaps helping Naruto with some of his Hokage - related duties so that he can have more time with Hinata.
Definitely Harry, Ron, and Hermione. They were the central characters during the war and would likely continue to be important in the post - war stories. They would be using their skills and experiences to shape the new wizarding world.