Who are the main characters in 'extremely loud and incredibly close true story'?
Since I don't know the exact 'extremely loud and incredibly close true story', it's difficult to say for sure. However, if we think about the kind of story the title implies, the main character might be someone who has a very personal and intense experience. There could be family members involved, like a mother or father, or perhaps a friend who plays an important role in the story. Maybe there is a mentor figure or someone the protagonist looks up to and their relationship is central to the story, especially if it has to do with the 'incredibly close' aspect.
Without having read the 'extremely loud and incredibly close true story', it's a guess. But often in such stories, there is a central figure, perhaps a young person. This young person could be the main character who is on a journey to understand something that is both extremely loud (a big, impactful situation) and incredibly close (related to their own family or personal life). There might also be secondary characters such as grandparents who hold the key to family secrets or a teacher who helps the main character make sense of the chaos around them. All these characters would interact to form the fabric of the true story.
