One possible reason could be that Sasuke in his curse seal form is much stronger. His physical strength and chakra levels are enhanced, making it difficult for Sakura to break free. Another reason might be that Sakura is in a state of shock or confusion, which hinders her ability to use her skills to free herself.
Well, there are several factors that could contribute to Sakura's inability to break free. Firstly, Sasuke's curse seal form likely gives him a boost in power that far exceeds Sakura's normal capabilities. His physical restraint might be accompanied by a suppression of her chakra, making it hard for her to gather the strength to break away. Secondly, Sakura's emotional state plays a role. If she is worried about hurting Sasuke or is simply in disbelief at his actions, she may not be fully focused on escaping. Additionally, the curse seal may have some sort of mental influence that makes Sakura more submissive or less likely to resist as forcefully as she could.
In the fanfiction, Sakura may not be able to break free because of Sasuke's curse seal - enhanced abilities. His speed, strength, and the dark chakra from the seal can overpower her. Also, Sakura might be hesitating to use her full force against Sasuke, as she still has feelings for him. This emotional conflict within her could prevent her from taking the necessary actions to break free.
Well, in many fanfictions, Sasuke's curse seal form often represents a more primal and uncontrollable side of him. So, it might make his actions towards Sakura more aggressive or unpredictable. He could be less rational and more driven by the power of the curse seal, which might lead to him restraining Sakura in a way that is more forceful than his normal self would be.
It could also be related to Sakura's strength. Sasuke is constantly striving to become stronger. If Sakura somehow shows a weakness or makes a mistake during a fight that he thinks could have been avoided, and it has negative consequences for their situation, he might get angry at her for not being more capable.
Sakura might grow tired of Sasuke's cold and distant behavior. In fanfiction, she could realize that she's been trying too hard to hold on to a relationship where she's not getting the love and attention she deserves. Maybe she meets someone else who shows her more care and respect, which makes her consider breaking up with Sasuke.
One possible reason could be Sasuke's continued obsession with his revenge - even after they got married, his focus on past grudges might have driven a wedge between them. Another could be differences in their life goals. Sakura might have wanted a more settled family life, while Sasuke was still drawn to his wandering ways in the name of protecting the village from afar.
Protectiveness. Sasuke has seen a lot of danger in his life. He knows Sakura is a valuable person, both as a friend and as someone he cares about. So his possessiveness could stem from his desire to keep her out of harm's way. He doesn't want any bad guys to get near her.
One possible plot could be that Sasuke, with his snake - related powers or abilities, restrains Sakura in a non - harmful way as part of a training exercise. He might be trying to teach her how to break free from unexpected restraints in battle situations. For example, he could use his snakes to hold her arms gently while she tries to use her medical ninjutsu skills and strength to escape.
Sasuke might believe that he's a danger to Sakura. Given his associations with dangerous elements and his own dark powers, he may feel that getting close to Sakura would put her in harm's way. Therefore, he rejects her to protect her. This is a common theme in many fanfics where Sasuke is portrayed as having a strong sense of self - sacrifice when it comes to Sakura.
One possible reason could be that Sakura has finally grown tired of Sasuke's aloof and cold behavior towards her. She might have realized that she has been constantly chasing after him while getting little in return, so she decides to ignore him as a form of self - preservation.
Well, Sasuke's cold attitude could be a reason. He is often distant and unresponsive to Sakura's feelings in the original story, and in fanfiction, this can be exaggerated, making Sakura angry. For instance, if he ignores her attempts at conversation or help.
Perhaps he sees her as a threat. Sakura is a skilled kunoichi, and Madara may want to prevent her from interfering in his plans. So he restrains her to keep her out of the way.