Another situation could be a miscommunication. For example, Naruto misinterprets something Hinata says or does, and it leads to a big fight. Hinata, being a sensitive person, might feel deeply hurt by Naruto's reaction. And Naruto, being a bit oblivious at times, doesn't realize how much damage he's done until it's too late and she decides to leave.
One possible scenario could be that Naruto makes a huge mistake in their relationship. Maybe he's so focused on his duties as Hokage that he neglects Hinata's feelings. He might start taking her for granted, not spending enough time with her or not being there for important moments in her life.
Well, it could be a situation where Hinata is trying to protect someone else from Naruto, perhaps believing he is a threat at that moment due to some false information. She might then end up hurting him while trying to fend him off. Or, in a darker fanfiction, there could be an alternate universe where Hinata has turned evil and deliberately targets Naruto to cause him harm.
One possible scenario could be Naruto and Hinata being shocked by the unexpected match - ups in the death battles. Maybe they'd be cheering for their favorite characters or be completely baffled by some of the outcomes.
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.
There could be a scenario where Naruto doesn't really understand the significance of the kiss at first. But Hinata is deeply affected and starts avoiding Naruto. This makes Naruto wonder what he did wrong and he tries to find out. As he tries to figure things out, he starts to realize his own feelings for Hinata might be more than just friendship. In some fanfictions, this also might attract the attention of other characters who have an interest in either Naruto or Hinata, causing some jealousy and drama.
It might occur when Naruto is training hard and gets injured. Hinata comes to his aid, tending to his wounds. As Naruto looks at her with gratitude, he realizes his true feelings for her. Hinata, seeing the look in his eyes, blushes deeply. Then, slowly, they share their first kiss, a tender moment filled with unspoken love.
One possible plotline could be Naruto's struggle to adapt to his new disability. He might have to relearn his ninja skills, like how to fight and perform jutsus with only one arm. This could lead to him developing new and unique techniques that rely more on his chakra control and his legs for mobility.
Maybe in the fanfiction, the situation is more complex. Hinata is being held hostage by the Cloud in a heavily guarded location. Naruto infiltrates the place secretly. He uses his transformation jutsu to disguise himself as a Cloud ninja at first to get closer. Then, he reveals himself and uses his Sage Mode to take on all the guards. He finally rescues Hinata and they escape together.
Another situation might be Naruto helping Gaara with his personal growth. Gaara has had a difficult past and Naruto, having overcome his own inner demons, could offer advice on how to better connect with the people of Suna and gain their trust even more. He could teach Gaara about the power of friendship and how it can make a leader even stronger.
A possible scenario is that Naruto discovers Hinata's dad is planning to arrange a marriage for her against her will. Naruto then steps in and tells him that Hinata should have the freedom to choose her own partner. Another scenario could be that Hinata's dad is being too hard on her training, and Naruto intervenes, saying that Hinata needs a more balanced approach to grow as a ninja.
Their married life in fanfiction may also include quiet moments. For example, they might sit on the porch at night, looking at the stars and just enjoying each other's company. Hinata could be the one who keeps the family grounded while Naruto is out there protecting the village.