In the fanfiction, it could be that Naruto and Hinata are just showing more public displays of affection. Sakura, being part of their close - knit group, feels left out and jealous. Her jealousy manifests as a headache because she's constantly thinking about their relationship. She might also be comparing her own love life to theirs and feeling inadequate. Maybe she starts to avoid Naruto and Hinata, which only makes her headache (both literally and figuratively) worse as she struggles with her feelings alone.
Well, perhaps in this fanfiction, Naruto and Hinata get engaged. Sakura has always been competitive with Hinata in a way, and now she's jealous. Her jealousy turns into a headache when she realizes that Naruto truly loves Hinata and she has no place in his romantic life. She might start to question her own relationships and how she's been treating Naruto all this time, which just adds to her mental turmoil.
One possible plot could be that Naruto and Hinata start dating. Sakura, who might have some unresolved feelings or just be used to Naruto's attention, starts to feel jealous. This jealousy could cause her stress and headaches as she tries to deal with her emotions. Maybe she sees Naruto and Hinata being affectionate and it makes her realize she lost her chance with Naruto in a way that really hits her hard.
The relationship between Naruto and Hinata could be developed further by them having to deal with Sakura's jealousy. They might initially be confused by Sakura's behavior but then come to understand that she's having a hard time adjusting to their new relationship status. They could try to be more sensitive around her, which in turn strengthens their bond as they face this external issue together.
Another plotline could be that Naruto is completely oblivious to Hinata's jealousy. He's just focused on his own goals and his friendship with Sakura. Hinata, on the other hand, is constantly in turmoil. She might start avoiding Naruto for a while out of embarrassment and confusion. But then Naruto realizes something is wrong and has to figure out what's going on between them, which makes for a very engaging story.
A plot could be that Sakura discovers that Ino has a crush on Naruto. Sakura, who also has feelings for Naruto, becomes extremely jealous. She starts to act cold towards Ino and tries to sabotage Ino's attempts to get closer to Naruto. Ino, noticing Sakura's behavior, retaliates. Naruto is caught in the middle, not fully understanding why his two friends are acting so strangely. This could lead to a series of misunderstandings and reconciliations as the story unfolds.
The plot could start with Sakura getting a lot of attention from other ninjas because of her new medical jutsu. Sasuke, who has always been reserved about his feelings for her, starts to feel jealous. One day, he sees her being praised by a group of ninjas and he can't take it anymore. He pulls her aside and gives her a sudden, jealous kiss. This kiss could be the turning point in their relationship, making them finally admit their feelings for each other.
There's a fanfic called 'Jealousy's Stirrings'. It delves deep into Naruto's jealousy when it comes to Hinata. The author does a great job of showing how Naruto's feelings for Hinata have grown over time and how his jealousy is a sign of his deeper love for her. It also has some action scenes intertwined with the emotional drama.
One common theme is the discovery of Naruto's true feelings. His jealousy often serves as a catalyst for him to realize how much Hinata means to him.
The fanfic could also explore Sakura's jealousy in a more emotional way. Maybe she starts to distance herself from Naruto because of the fangirls. But then she realizes that she misses him and that her jealousy was really a sign of her deeper feelings for him. This could lead to a moment of realization for Sakura and perhaps a change in their relationship. For instance, she might become more open about her feelings towards Naruto instead of bottling them up like she often does.
Well, it could be about Naruto and Hinata starting a family. They might face challenges in rebuilding the village after the war, like dealing with the orphans and making sure everyone has a home. Maybe Naruto has to balance his Hokage duties with being a good husband and father.
Often, the jealousy Hinata feels acts as a catalyst. It makes her more determined to get closer to Naruto. So, she starts to be more confident around him. Naruto, seeing this new side of Hinata, becomes more interested in her. Their relationship then moves from Naruto just seeing Hinata as a friend to seeing her as someone he could have a deeper connection with.
Maybe it's because of Naruto. If Hinata has a closer relationship with Naruto than Sakura does in the fanfiction, Sakura could be jealous. After all, Sakura has her own feelings for Naruto.