Shikamaru could be another helper. He's smart and good at planning. He might assist Naruto in coming up with a creative and fool - proof plan for the proposal, making sure everything goes smoothly and Hinata is completely surprised in a positive way.
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.
Hinata would be overjoyed. She has loved Naruto for a long time, so his proposal would be like a dream come true for her. She might start crying tears of happiness and immediately say yes without hesitation.
Iruka sensei could also be very helpful. He has always been like a father figure to Naruto. He would support Naruto through this strange transformation, offering advice on how to handle the reactions of others in the village and how to adapt to this new situation without losing sight of his ninja goals.
In a fanfiction, Naruto might plan a big public proposal. He could gather all their friends and family in the Hidden Leaf Village. He would make a big speech about how Hinata was the one who saw him when others didn't, and her love changed him. Then, with everyone watching, he would pop the question.
I think Gaara could be an ally. Gaara has control over sand and is very powerful. He and Naruto have a mutual respect for each other. Additionally, Jiraiya. Jiraiya was Naruto's mentor and has a vast knowledge of different jutsu and combat techniques that could be used against Omega Shenron.
Another possible antagonist could be a rogue ninja from Hailbel's past. This ninja could have a vendetta against her family or something she did in the past. When he discovers that Hailbel is with Naruto, he decides to take them both on. He might have some unique and dangerous techniques that Naruto and Hailbel have to figure out how to counter.
Ninjas, of course! They would come to relax after a long day of training or missions. Also, fans of the ninja world from within the story would be there. Maybe even some of the village leaders would stop by to show support for the local business.
Iruka - sensei would be very likely to help. He was Naruto's first teacher and has always cared about him. He could use his teaching skills to reteach Naruto things he's forgotten. Hinata would also be there for Naruto. Her love for Naruto is strong, and she would do anything to help him. She might use her Byakugan to look for any physical problems in Naruto's body that could be related to his memory loss. And of course, Jiraiya. If he were still alive in the fanfiction, he'd be a great help. He trained Naruto and knows him well, so he could use his sage knowledge to assist in getting Naruto's memory back.
Sakura would probably be the first one to help. She's a medic - nin, after all. She has the skills to monitor his condition and develop treatment plans.
Sasuke would be a likely ally. They have a long - standing relationship and have fought side by side before. Sasuke's Sharingan and his own unique abilities would be a great asset against the Ten - Tails.
Ruby Rose for sure. They both have a strong sense of justice and a desire to protect others. Naruto would be intrigued by Ruby's scythe and her use of Dust. And Ruby would be interested in Naruto's ninja tools and jutsu.