It could be that the side story focuses on a new character who has a significant impact on the existing stranger - than - friends relationships. This new character could be a catalyst for change or a source of new revelations. However, without reading it, it's hard to say exactly who the main characters are, but they are likely to be related to the central themes and relationships of the main 'stranger than friends' story.
Most likely, the characters who had the most complex or interesting relationships in the original story would be the main ones in the side story. They might be the ones whose stories need further exploration, like a character who was always a bit of an enigma in the main plot and now gets a chance to have their story told more fully in the side story.
I don't know for sure, but probably some of the main characters from the 'stranger than friends' main story would also be important in the side story.
I'm not entirely sure as I haven't read it specifically. But generally, a side story might expand on the relationships or events that were only hinted at in the main 'stranger than friends' story.
In the book 'Stranger than Fiction', Harold Crick is the main character around whom the whole story revolves. He's a rather dull and routine - bound man at the start. Then there's the mysterious narrator. This narrator has a huge influence on Harold's life as they seem to be in control of the narrative of his life. Other characters include those in Harold's workplace, such as his boss and coworkers, and some of the people he meets during his attempts to figure out what's going on with his narrated life. But Harold and the narrator are the two characters that really carry the story forward.
The main character is Harold Crick. He is an IRS agent whose life takes a strange turn when he starts hearing a voice narrating his life.
One interesting story could be about unexpected friendships that form in the most unlikely circumstances. For example, two characters from different backgrounds who initially clash but then find common ground and become closer than they ever thought possible.
The main character is Harold Crick, played by Will Ferrell. He's an ordinary man whose life gets turned upside down when he hears the narration. Another important character is Ana Pascal, a baker that Harold falls in love with. And there's also Professor Hilbert, who helps Harold understand the situation he's in.
Harold Crick is the central character in 'IMDb Stranger Than Fiction'. He's an IRS auditor whose life is turned upside down by a narrating voice. Ana Pascal is another main character. She's a feisty baker who has her own charm. And then there's Professor Hilbert, who tries to help Harold figure out what's going on with the voice in his head.
It's likely that 'stranger than friends side stories' contains a collection of tales that delve into the gray areas between different types of relationships. Maybe it shows how some relationships start off in an unusual way, not like the normal friendship beginnings. There could be stories about people who have a connection that is hard to define, neither just friends nor something else entirely at first, and how these relationships evolve over time.
Sasuke could also be a main character. In many Naruto - related stories, Sasuke plays a crucial role, and in a fanfic like 'naruto stranger than the wild', his relationship with Naruto and his own journey might be explored in a new and different light.
The main characters would almost certainly include Eleven, given her unique abilities and her importance in the overall Stranger Things narrative. Mike, who has a special connection with Eleven, would also be a main character. Dustin and Lucas, with their distinct personalities and contributions to the group, are likely to be there as well. And Will, whose experiences in the Upside Down have been a major focus of the series. There might also be other important characters from the show, like Joyce, Will's mother, or Hopper, the police chief, as they often play crucial roles in the story and could be just as important in the graphic novel.
Well, the main character is probably the stranger. There might also be characters who interact with the stranger, such as the people in the place where the stranger arrives. They could be locals or people who have their own lives and routines that are disrupted by the stranger's presence.