There could be original characters created specifically for this fanfic. These new characters might be the source of Sakura's anger. For instance, a new villain who has targeted Sakura or her loved ones. Or it could be a rival who constantly undermines Sakura, causing her to be angry. Additionally, characters from other related series might make cameo appearances if it's a crossover - type fanfic.
Obviously, Sakura herself is the main character. Naruto could also be in it. Maybe he tries to convince Sakura to stay or he could be the one to help her prepare for her journey. Sasuke might be another character. He could have some influence on Sakura's decision to leave, either by his own actions or just his presence in the village.
Obviously, Sakura's sister would be a main character. Sakura herself might also be in it, as well as their friends. There could be a cute animal sidekick too, like a talking cat or a little fairy.
A 'sakura angry fanfic' could be centered around Sakura's emotional state of anger in various scenarios. It might be set in the world of an anime or manga where Sakura usually has a more calm or composed demeanor, but in this fanfic, something has pushed her to the edge. It could be related to unrequited love, a betrayal by someone she trusted, or a threat to her home or community. The story might then explore how she deals with this anger, whether she channels it into something positive or lets it consume her.
There could be the narrator, who is the one trying to get away from Sakura. Maybe there's also a best friend of the narrator who encourages them to break free from Sakura. For instance, this friend might see the negative impact Sakura has on the narrator's life and gives advice on how to get away.
Obviously, Italy itself would be the main character. There could also be other European countries like France and Germany. They might be the ones causing Italy's anger, or they could be Italy's allies trying to calm it down.
One character that could work well with an angry Loki is Doctor Strange. Strange is used to dealing with powerful and unpredictable entities. He could either try to manipulate Loki's anger for his own purposes or try to help Loki come to terms with it. And of course, Sif. She has a history with Loki and her loyalty to Asgard could put her at odds with an angry Loki.
There could be the prison guards. Some might be cruel and strict, while others could be more sympathetic. Also, other inmates. Maybe an older, experienced inmate who becomes a mentor - like figure to Sakura.
It's also possible that her adventure - team friends betray her. In a fictional world, if there are some high - stakes situations like a quest for a powerful artifact, they could betray her for their own gain, such as getting the artifact all for themselves.
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.
Obviously, Sakura would be the main character. Her teammates like Naruto and Sasuke could also be important characters. Their interactions with Sakura would play a big role. Also, her sensei, like Kakashi, might be in the story to guide her. There could be other genin from the village as well, either as friends or rivals.