You can check out 'Harry's Struggle in Peace'. It's a fanfic that focuses on Harry's inner turmoil after the war. He's suffering from PTSD and has a hard time adjusting to a world without Voldemort. The fic shows his journey of trying to find meaning in his life again.
I would recommend 'Harry's Post - War Blues'. In this fanfic, Harry is not the triumphant hero everyone expects him to be after the war. He is constantly haunted by nightmares of the final battle and feels isolated even among his friends. The story shows how he slowly tries to heal himself with the help of some unexpected allies in the wizarding community.
In fanfiction, Naruto could be depressed after the war because he realizes that the world he fought for is still full of problems. The shinobi system might still be corrupt in some ways, and he may feel that all his efforts haven't really changed the fundamental issues. He might also be suffering from post - war stress disorder, constantly reliving the battles and the horrors he witnessed.
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.
He might become very self - reliant. Since he has no one to depend on, he learns to take care of himself in every aspect, like finding his own place to live and getting food. He could also start to study magic more independently, exploring areas that were previously forbidden or not well - known.
One possible story could be that after the war, Harry suffers from paraplegia due to some dark magic he endured during the final battle. Ginny stays by his side, being his strength. She helps him through the difficult process of physical therapy. Their love becomes even deeper as they face this new challenge together.
Some fanfictions might depict them as having a more adventurous post - war life. They could be involved in rebuilding the wizarding world in a more hands - on way. Harry might use his fame and Ginny her popularity among the younger wizards to bring about positive changes. Their relationship would be based on mutual respect and a shared goal of making the wizarding world a better place.
Harry might become more at peace. After all the battles and losses, he could focus on the positive aspects of life. Luna, on the other hand, could become more confident in sharing her ideas. She no longer has to be in the shadow of the war and can be more outspoken.
They could become very close friends. After the war, they both have a shared understanding of the trauma and changes they've been through. They might support each other in rebuilding their lives at Hogwarts or in the wizarding world in general.
One possible reason could be that Harry was away a lot after the war, dealing with the aftermath and his newfound responsibilities. Ginny might have felt neglected. Maybe she expected more time together, but Harry was constantly occupied with things like helping to rebuild Hogwarts or being involved in the Ministry's new initiatives.