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.
In addition to Sakura, there could be some original characters created for the fanfiction. Maybe a new genin who becomes Sakura's best friend or a tough rival. The Hokage at that time, whether it's Tsunade or someone else, might also make an appearance. They could give Sakura special tasks or offer advice. And of course, the various shopkeepers and villagers in Konoha could be part of the background characters to add more realism to the story.
It could be about Sakura's journey as a genin during a particular year. Maybe she faces tough challenges, makes new friends, and overcomes her weaknesses. For example, she might have a rivalry with another genin that pushes her to train harder.
Sakura as a strong Genin in fanfiction often has her character developed further. She could be shown to have a better understanding of chakra control, which allows her to perform more complex jutsu. Some fanfictions might also give her a unique kekkei genkai that makes her stand out. This could be something related to her already existing skills, like a form of enhanced sensory perception for medical ninjutsu, enabling her to detect internal injuries more accurately.
One great Sakura Haruno Genin fanfiction is 'Sakura's Growth'. It shows her development as a genin in a very realistic way. It focuses on her training, her relationships with her teammates, and how she overcomes her insecurities. Another good one could be 'Genin Sakura's Adventures' which has her going on various missions and learning new jutsu along the way.
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.
Obviously, Sakura's mother herself. And her family members like her parents or siblings if they are relevant to the story. They could have influenced her in different ways.
In fanfiction, Sakura's intelligence is sometimes magnified. She becomes a master strategist, able to anticipate her enemies' moves. This, combined with her medical skills, makes her a force to be reckoned with. She can use her knowledge of the human body to find weak points in her opponents during combat, not just for healing.
Sakura's growth as a genin is a major factor. At this stage, she's still learning and has a lot of room for development. Fanfictions can show her learning new jutsu, improving her combat skills, and becoming more confident. Also, the genin missions she goes on can be full of adventure and danger, which makes for exciting reading. In some fanfictions, she might face challenges that the original story didn't fully explore during her genin days.
One possible member could be a young ninja with a natural talent for earth - style jutsu. He's a bit of a loner at first but slowly warms up to the team. Another member could be a girl who is really good at tracking and has a sharp mind. And then there might be a Genin who is from a family known for their medical ninjutsu skills, just like Sakura, and they look up to her a great deal.
Sakura might also be a main character. She could play a role in helping Naruto with his eternal genin status, perhaps by providing medical support or strategic advice during his missions as a genin.
A powerful dragon that guards the school's most precious treasures could be one of the characters. Also, there might be a group of elves who are experts in nature magic and they could be either friends or rivals to Sakura. Another possibility is a half - human, half - phoenix character who has the ability to heal with fire.