Perhaps it's a part of a more complex scenario in the fanfiction world. Itachi could be under some sort of mind - control or spell, and Sakura is an unintended victim. Roping her wrists might be an action that is out of his normal character but is a result of the external influence on him.
It could be a story where Itachi has some sort of ulterior motive for restraining Sakura. Maybe he's trying to protect her in a very unorthodox way. For example, he might be aware of a danger that only he can sense, and by restraining her wrists, he's ensuring she doesn't run into harm's way.
It could be Orochimaru. He's always had an interest in powerful shinobi, and Sakura has shown great potential. Itachi might be roping Sakura's wrists to prevent Orochimaru from getting to her and using her for his evil experiments.
Itachi might be doing this as a means of restraint to prevent Sakura from interfering in a dangerous situation. He may know that she has a tendency to rush into things without thinking, and this is his way of ensuring she stays put. Another idea is that it could be related to a cultural or ritualistic practice within the context of the fanfiction's world.
Sakura could also be confused. She may try to reason with Itachi, asking him why he is doing this. If she trusts him to some extent, she might be more compliant while still expressing her discomfort. She may start to analyze the situation, trying to figure out if there is a hidden meaning or purpose behind his actions.
Fanfiction is fictional stories written by fans. In this case, it might be about a scenario where Itachi pins Sakura's wrists. It could be part of an action - filled, or perhaps a more complex and dramatic story within the fan - created world of the relevant anime or manga.
I'm not sure if it's a particularly popular type. There are so many different kinds of Naruto fanfiction out there, focusing on various relationships and scenarios. While the idea of Itachi and Sakura interacting in this way might be interesting to some, it may not be as widespread as other more common pairings or plotlines.
Well, perhaps the plot could involve Sakura being assigned as Itachi's secretary in a powerful ninja organization. At first, Itachi is cold and distant towards her, but Sakura is determined to do her job well. As time passes, they start to have mutual respect for each other's skills. Then, an external threat to the organization emerges, and Sakura and Itachi have to work together closely, which leads to a deeper understanding and maybe even the start of a romantic relationship between them.
Perhaps in the fanfiction, Sakura and Itachi are in a police force that has to deal with international ninja disputes. Sakura, with her intelligence and strong will, and Itachi, with his strategic mind, work together to prevent a full - scale war between two large ninja clans. They face many challenges along the way, including distrust from their own comrades who are skeptical of their unorthodox methods.
The plot could involve Itachi noticing Sakura's isolation within her own team at some point. He decides to adopt her in a sense, like becoming a mentor to her. Itachi could share his insights on how to deal with powerful enemies and the sacrifices one has to make for the greater good. Sakura would then grow not only in her combat skills but also in her understanding of the complex world of ninjas. She might start to see things from a different perspective, similar to Itachi's, which could cause some friction and also growth within her relationships with Naruto and Sasuke.
One possible plot could be that Sakura, with her new family connection to Itachi, gets trained by him in secret. This would make her much more powerful and give her an edge in the ninja world. It could also lead to her being targeted by the same enemies as Itachi.
One possible plot could be that Itachi, in a world where he didn't have to carry out all the dark deeds he did in the original Naruto story, meets Sakura and is intrigued by her medical skills and strong will. He starts to want to get to know her better, which leads to a series of adventures where they team up to help the Hidden Leaf Village in some new and unexpected ways.