Lu Mingfei, a senior high school student, suddenly received an invitation letter from Kassel College. This great thing that fell from the sky made him a little overwhelmed. After a series of events, Lu Mingfei decided to face the unknown and join Kassel. Unexpectedly, he was told that Kassel's study journey was for - slaying dragons. Unusual events such as the college's "Free Day" and "3E" exams made him believe that he really joined a mysterious organization whose goal was to slay dragons. The subsequent action to Bronze City also made him face his extraordinary and cruel life that had already arrived...