Murder Mystery Competition

Two schools with the same origin - H University and Q University - are separated from the north and the south of China, but they are in love with each other. Infected by this atmosphere, the reasoning clubs of the two schools also refused to give in to each other. Every two years, they compete with each other with a "murder reasoning competition" that simulates murder incidents. Sometime in the 1970s, five members of the Mystery Association from Southern H University, led by president Qian Yifei, prepared to challenge a case carefully arranged by five members of Northern Q University, headed by Yao Pingwa, the president of the Mystery Association. However, in the famous "Old Study Room" where the members of Q University decided, the dispute between the northern and southern schools unexpectedly turned into a serial murder case! The dead appeared one after another, and their heads were chopped off. What is the motivation behind the mystery that challenges members of the two schools' reasoning clubs at the same time?