Kiba could be a side character. He might visit with Akamaru and have some friendly banter with Naruto and Hinata. Ino could also be in the story, using her mind - related jutsu to help with any mental stress that Naruto or Hinata might be facing. And the old - timers like Kakashi and Iruka could make appearances, offering their wisdom and support to the young couple as they start their life together.
Sakura would probably be a side character. She could be the one who checks on Hinata's health during her pregnancy if that's part of the story. Shikamaru might also be there, helping Naruto with some of the strategic planning for the village while also giving him relationship advice. And Boruto and Himawari would be important side characters as their children, adding a family - centered aspect to the fanfiction.
Obviously Naruto is one of the main characters. And then, there would be the Eevees. There could be a special Eevee that stands out, like an Eevee that is more curious about Naruto than the others and becomes his closest companion among the Eevees.
One of the likely supporting characters is Tsunade. Given her experience and leadership in the village, she could be a source of advice for Naruto and Hinata. She might also ensure that Hinata has the best medical resources available during her pregnancy. Rock Lee could be another supporting character. His positive attitude and loyalty to Naruto would make him eager to help out. He could be running errands for them or helping with any physical tasks. And Neji, if he were still alive in this fanfiction, would surely be there to protect his cousin Hinata and support Naruto as well.
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.
Obviously Naruto would be one of the main characters interacting with him. Naruto would look up to Sarutobi as a mentor and a source of knowledge. Their interactions could range from training sessions to deep conversations about the future of the village.
Naruto himself is very likely to be one of the main characters. After all, he is the central figure of the Naruto franchise.
Naruto would be a very likely character to interact with Hinata. Since they have a strong connection in the original story, in a time - travel scenario, their relationship could develop in new and interesting ways. Maybe Hinata could be more open with her feelings earlier in time.
Iruka sensei might also be involved. He has always been like a father figure to Naruto. He could give Naruto the confidence he needs and maybe even help him plan the location for the proposal, perhaps a place that has sentimental value for both Naruto and Hinata related to Naruto's early days at the academy.
In Naruto fanfiction, Hinata is often seen as a better match for Naruto. Hinata has been in love with Naruto for a long time. She has always supported him silently from the sidelines. Her gentle and shy nature can be a good complement to Naruto's more boisterous personality. Sakura, on the other hand, had feelings for Sasuke for most of the story, which makes her connection to Naruto seem less deep in comparison.
Sakura could be a common character. Since she has a history with Naruto, she might be part of the harem in some fanfictions. Also, Tenten could be included as she is another female ninja in the Naruto universe. And Ino, with her strong personality, could also be written into the harem scenario.
Harry is the central figure for sure. Neville Longbottom could play a role. He might be one of the few who know where Harry is hiding and is trying to protect the trunk from being discovered. Hagrid could also be involved. He might bring Harry some food and supplies while he's in the trunk. And there could be some mysterious old wizard or witch who has some connection to the trunk and its magic.