Hinata would likely become more independent. For example, if she was often relying on Naruto for emotional support, she'd have to find that within herself. She might become more assertive in the village, using her skills to protect it as Naruto did.
Hinata might become more determined. After crying over Naruto's death, she could realize that she needs to be stronger. So she might start taking on more leadership roles in the village, using her Byakugan skills more effectively.
His character may become more withdrawn at first. Losing Jiraiya, who was like a father figure to him, could make Naruto less open and more focused on his internal pain.
It could make Naruto more introspective. He might question his own worthiness of Hinata's sacrifice. This could lead to him delving deeper into his own beliefs and values. He may also become more empathetic towards others who have lost loved ones, as he now has first - hand experience of that kind of pain. He would grow in maturity, realizing that his actions have consequences not just for himself but for those around him who care about him deeply.
Hinata may become more assertive. Since she has Naruto as her 'weapon', she has to take on a more leading role. She might have to make decisions about when and how to use Naruto's powers, which could make her grow in confidence.
In many fanfictions, Hinata's confidence grows. For example, she might start taking on more leadership roles in missions with Naruto. Since she has always been shy, in fanfiction, she could break out of her shell more, especially when Naruto is in danger. She becomes more assertive in protecting him and their relationship.
In some fanfictions, Naruto is completely oblivious at first. He doesn't understand why Hinata is acting strange. He just goes about his day, being friendly as usual. But as Hinata's jealousy becomes more obvious, he might start to notice that something is wrong. He could be confused and try to ask Hinata what's bothering her.
Naruto's character develops by becoming more responsible. As Hinata's guardian, he has to think about her safety first. He becomes more perceptive of her needs and feelings. For example, he might notice when she's sad or scared even without her saying a word.
Naruto's character could develop by becoming more protective. After saving Hinata and Hanabi, he might realize how much they mean to him and the village. This could make him more vigilant in looking out for threats against them and the rest of the clan.
After the Pain arc in fanfiction, Hinata's character development in relation to Naruto is multi - faceted. Her love for Naruto, which was so boldly shown during the Pain encounter, now becomes a driving force for her growth. She may learn new skills or develop new aspects of her personality to better fit into Naruto's world. For instance, she could start learning more about Naruto's dreams and goals and find ways to support him more effectively. This would not only strengthen their relationship but also help Hinata grow as an individual character.
In these fanfictions, Hinata often develops more confidence. As Naruto's secretary, she has to interact with many people and handle important tasks. For instance, if she has to give presentations on Naruto's behalf, it forces her out of her shell. This new - found confidence can also affect her relationship with Naruto, as she becomes more assertive in expressing her feelings for him.