The book I am writing has several characters in it all of whom are interesting, they are all part of an informal group they don't know each other particularly well although in the end some will get to know each other in ways they didn't expect. Is it always necessary to have a main character in order to build a story that people will read? Do readers demand that one of them be the main character?
I haven't read the other responses but here's my tuppence worth ...
I believe you can have a story which follows multiple characters but I think the reader will respond better if they can determine who the main character is - who's story are they really following? If the storyline just chops and changes then they'll have to start afresh with who to 'care' for and it might be confusing or, at worse, a turn-off.
Hope the writing goes well and you manage to figure it out so that it works.
Well, I've read a book called Time Riders- it was an amazing work and there are 3 protagonists actually and now it's a series of books numbering up to 9. So, yes it is possible but I personally don't opt for it.
There should always be a main character that appeals to the reader. Its our interest in the protagonist that keeps us turning the pages.
The casual reader might not think there is a main character in 'Little Women' by Louisa May Alcott. Amy, Beth, Jo and Meg are sisters, they all have tremendous appeal, but Jo is the main character.
A would-be author has no chance of being traditionally published without a protagonist.