A couple of times now I've seen something where writers, or even editors or agents say they want diversity in novels. Where they want a black main character or something.
Personally, I think it's really dumb.
My goal as a writer isn't to have the most diversified cast of characters. My goal (or at least one of them) is for the person who is reading the book to be so caught up in the story it doesn't matter what color the main characters skin is, or where they are from. And Personally, I think it should be your goal too. If the reader needs the character to be a certain someone for them to relate (as in Asian or Canadian or African or such) than they aren't the right reader.
If I ever get a book published, I don't want people to be like, "Oh my goodness, her character has blonde hair?! I can't read that!" The complete opposite actually. I don't care if, at the end of the story, they remember the color of her hair, or even if they don't remember the story at all. I want them to learn something, or to be touched, to take something away from the story they didn't have before.
So, is it important for there to be diversity in characters in your story? I don't know. Only you can decide what's important in your story.
(On the other, if you are writing about, say, a black person during the '50's and segregation was a big deal then yeah, it's important. Because it has something to do with the plot. The character isn't different just to be different.)
(and I'm not saying I'll never write a story with an Asian main character or what not, but I'm not going to specifically make a point of it just because there is a supposed need.)