Does the mangaka have any bias for/against any character?

I really love the anime and intent to start reading the manga once I finish the one I'm currently reading but 40+ volumes seems to be a huge investment so I want to know if the mangaka has any positive/negative bias towards any character that reflects in her work which could negatively affect the story. One of my childhood favorite series was completely ruined because of how much the author favored one character and hated another (who happened to be my favorite) so I'm just being cautious.

Please keep it short without giving any major spoilers. Thank you.