Ten years ago, civil strife broke out among the demon clan. In order to find the new demon king, the elder brother of the brothers was kidnapped. Before leaving, he said to his brother Yu: "I will be back soon." Ten years later, his brother did not come back. At this time, Yan received a mission to take the academy students to detect demons. What will he encounter? Will he encounter trouble? This is the author's debut novel, please feel free to comment if there is anything wrong with it. Please give me more advice~