Perhaps it's a case of mistaken identity. The ones who strapped her down might have thought she was someone else who had wronged them. In the chaotic world of the wizarding war, misinformation can easily lead to such situations. It could also be a test of some sort, set up by a powerful and perhaps unethical wizard who wants to see how she'll react under extreme stress and duress.
One possible reason could be that she has been captured by some dark forces who want to extract information from her. They might think she has valuable knowledge about the Order of the Phoenix or some powerful magic. Another reason could be that it's a part of a dark ritual. Some evil wizards or witches might believe that her magic or her connection to certain powerful magical artifacts can be harnessed in this way for their own malicious purposes.
It could be related to a plot by a group of rogue wizards who are trying to break her will. They might want to turn her to their side, and by strapping her down and subjecting her to various threats or manipulations, they hope to make her more pliable. This could be part of a larger scheme to gain control over Hogwarts or the entire wizarding world through Hermione, who is known for her intelligence and magical abilities.
Harry would be extremely angry and immediately rush to her rescue. He has a strong sense of loyalty towards Hermione and would not tolerate her being in such a dangerous situation. Ron, on the other hand, would also be very worried. He might start panicking a bit at first but then quickly gather his courage and follow Harry's lead in trying to free Hermione.
One possible reason could be that she was attacked by some dark creatures while on a solo adventure in the Forbidden Forest. The forest is full of dangers, and Hermione, being brave and curious, might have ventured too deep and got injured by a creature like a werewolf or a giant spider.
In some fictional stories, it could be for power and control. If the woman is in a position of authority, she might strap the teen boy to assert her dominance.
In some fanfictions, it might be part of a dark plot. There could be a powerful dark wizard or witch who has the ability to manipulate people's minds. They make everyone believe that Hermione is a threat and thus cause them to abandon her. This can add a lot of drama and conflict to the story.
One reason could be the saturation of the market. There are so many Naruto fanfictions out there that it's hard for new ones to stand out. Another factor might be the decline in the overall popularity of the Naruto franchise over time, leading to less interest in its fan - created content.
One possible reason could be that she is facing a powerful dark wizard who wants to assert dominance over her. Maybe the villain is trying to break her spirit as she is known for her strong will in the original story.
It could be a matter of power dynamics. In some fictional scenarios, the female might be in a position of authority and the teen boy has violated some rules. So, strapping him is a form of discipline. Like in a story where a female is the leader of a secret society and the teen boy is an initiate who has broken a sacred oath.
One possible reason could be that she was captured by some dark wizards who oppose her and her friends' actions. They might see her as a threat due to her intelligence and magical abilities. Another reason could be related to a misdirected spell or curse. Maybe someone was aiming for another target but accidentally hit Hermione and then tied her up to prevent her from seeking help immediately.
Another reason could be a rift in their friendship caused by outside factors. For instance, if the wizarding community starts to turn against Harry because of false rumors or misinformation, Hermione might find it too difficult to stand by him. She may fear for her own reputation or safety, and this could lead to her abandoning Harry.
One possible reason could be the stress from her studies. Hermione is always under a great deal of pressure to excel academically. Maybe she reached a breaking point due to the overwhelming workload. Another reason might be some kind of conflict with her friends. For example, if she had a big fight with Harry or Ron over something serious, it could leave her feeling broken.