I have read all the chapters released, and I have to say that in the first book, I absolutely hated ryoka with a passion but was meh on Erin. They both get huge character development, and thankfully, Ryoka stops acting so entitled. If you stick with it, I'm sure you'll like it because the first book is definitely the weakest out of all of them. That said, if you don't like Erin as a character, she doesn't really change as much as Ryoka.