The protagonists of this book are Shang Dongxue and Di Xiafeng. They have been good friends from birth to life and death. They have learned martial arts since they were young and have a strong sense of justice. During the summer vacation, they met Bai Sally who worked in a cafe and became friends with her. From 4 Sally, who was obsessed with detectives at the age of 10, often helped Shang Dongxue and Di Xiafeng solve cases. Later, they met Shen Lang, the leader of the "Axe Gang" by chance, but Shen Lang later returned to the right path and became kind and enthusiastic. When Sally and the three of them were solving the "Axe Gang" case, they met again. He met Shen Lang's rival Yue Lingkong, but because Shen Lang had entered the righteous path, he became friends with Shen Lang again. Lingkong was a very mysterious but kind-hearted man with unparalleled martial arts skills who often helped Shang Dongxue and the others. Shang Dongxue's deskmate Ling Feng, known as the Smiling Prince, But what connection does he have with this world? In the book, four chivalrous knights with the same integrity as Shang Dongxue appear. Because of these brave chivalrous women and heroes, the entire Kuzu City has become righteous, because chivalry will never be extinct!