I'm not completely sure what your asking, but I have two answers for you.

If you want to know if you can use other characters "instead of Bao Bei", I would say no, Bao Bei is the focus of the story.

If you want to know if you can include other characters into the story as well as Bao Bei, go for it, just don't kill them if you didn't create them.

I hope one of these answers your question. :)