There could also be new characters created specifically for this fanfiction. Maybe a character who has the ability to control all forms of paper in the Naruto world and becomes either an ally or an enemy to Naruto. This new character could bring new dynamics to the story and its plot.
I'm not sure specifically as it's a fanfic, but it could include Naruto himself. He might have a special connection to the chakra paper in this story.
In Naruto paper bloodline fanfiction, Kakashi can be a popular character. His intelligence and wide range of skills can be combined with the paper bloodline in interesting ways. For example, he could use his Sharingan to copy and improve paper - based jutsu. Also, characters like Sakura could be given a paper bloodline in some fanfictions, and she might use it to enhance her medical ninjutsu, like creating paper bandages that have special healing properties.
Konan would be an obvious choice as she already has the paper release ability in the Naruto series. Fanfiction could expand on her powers and her backstory, like exploring her training in more detail or her relationships with other Akatsuki members.
Sasuke could be in it. He might be initially skeptical of Naruto's new power but then see its potential in combat.
I don't know specifically as I haven't read it, but probably the paper girls themselves are the main characters.
Since I haven't delved into 'the paper chase novel', it's difficult to say exactly who the main characters are. However, based on the title, we can assume there might be a protagonist who is deeply involved in the chase related to the paper. There could also be an antagonist who is either causing the need for the chase or trying to stop the protagonist from achieving their goal regarding the paper. There might also be supporting characters like friends or colleagues of the protagonist who help or hinder the chase in different ways.
Perhaps the main characters are a young couple. In a story about love and creativity, the two of them could be involved in making paper stars together, with each star representing a moment in their relationship. It's also possible that the main character is an artist who uses paper stars as part of their art, and the story follows their creative process.
Since I don't know the details of the 'paper star story', I can't say for sure. It could be a little girl who loves making paper stars as the main character.
Since I don't know the exact 'paper man story', it's hard to say. But likely the paper man himself is a main character. There might also be someone who created him, if it's that type of story.
The obvious main character would be the paper boy. He could have a family, so his parents or siblings might be important characters too. For example, his father might be unemployed and the paper boy feels pressured to do well in his job to help the family. There could also be a rival paper boy in the area, competing for the best routes or the most customers, and this rival could be a main character in the story as well.