Book arrangement task is still executed by humans, and it has not been mechanized, yet. So, we are developing a book arrangement robot system. Our developed system can insert the grasping book to the narrow gap in the bookshelf or in case the side book is inclined. We have constructed an operation by the robot arm based on the human operation. Physical models of the book for examining the conditions necessary to widen the gap of the books are generated. We evaluated whether the robot can widen the gap of books or not by using this physical model and confirmed the generated book insert operation by the robot arm through experiments.