As said in the title....
1. Roleplay with anybody but ask permission from the person first
2. All you have to do to roleplay for the new ones is to write a comment. In my book, no need to ask permission to roleplay, just follow rule 1!
3. Don't fight or bully that stuff
4. HAVE FUN!!!!! The most important thing is what I just said before!
Just role play with anyone you choose, meaning any character or let's say, idol. Human or character, doesn't have to be restricted to anime and such.

Just have fun role playing that is what this book is about!