The title of the 30th volume of a Japanese fantasy novel,"Goodbye, My Friends," is a summary of the whole novel and a reminder to the readers. In the novel, Charlie IX experienced many adventures and challenges and made many friends. As the story progressed, the relationship between Charlie and his friends also changed. Sometimes there would be contradictions and differences between them, but in the end, they could still unite and face the difficulties together. Therefore, the phrase "Goodbye, my friends" expressed the deep friendship and unity between Charlie and his friends, and also wished that they would be able to meet again in the future.