One possible plot could be that Harry and Hermione travel the wizarding world together, documenting all the post - war changes. They might visit Hogwarts, which is being rebuilt, and help in the restoration process, reminiscing about their old school days as they do so.
They could become even closer friends. After going through the war together, they have a deep bond. Maybe they start to rely on each other more than ever, sharing every little detail of their lives.
One great fanfic could be where they travel the wizarding world together to help rebuild the places damaged during the war. They use their combined knowledge and skills to bring back the former glory of Hogwarts, for example. Hermione's intelligence and Harry's leadership make them a formidable team in this post - war setting.
Hermione, on the other hand, could become more confident in her leadership skills. In the post - war fanfic, she may take on more responsibilities in the wizarding community. With Harry by her side, she realizes that she can make a real difference. Her character grows from being the brains behind Harry's operations to a leader in her own right. She also becomes more open - minded about different ways of magic, as she and Harry explore new areas of the wizarding world together.
Their relationship might start with them being comrades in arms. After the war, they would have more time to really talk and understand each other on a deeper level. This would lead to romantic feelings.
Well, it could be about them rebuilding their lives. Maybe they start a family and deal with the post - war traumas together. They might also be involved in the restoration of Hogwarts, using their magic skills to bring it back to its former glory.
One possibility could be that she begs for the truth. In a lot of fanfics, when Hermione is betrayed, she might beg the person who betrayed her, perhaps Harry if the plot is set that way, to tell her why they did it. She's a character who values loyalty and knowledge, so being betrayed would be a huge shock. And her begging could be a way to try and make sense of the situation, to get back to the stability she once knew.
One possible plot could be that after the war, Harry and Hermione realize they have a deep bond that goes beyond friendship. They start to rebuild Hogwarts together and in the process, their feelings grow. They get married in a small ceremony at Hogwarts with their closest friends in attendance.
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.
One common theme is healing. Harry has been through a lot during the war, so in these fanfics, he often has to deal with his emotional and physical scars. Another theme is rebuilding. The wizarding world is usually in shambles after the war, and Harry is involved in putting it back together.