The story tells the story of Hideo Homura (Saito Ko), an associate professor of Sociology at Yingdu University, who was commissioned by the police to assist in the investigation of a murder case. However, there is a dark side in his heart. He once admitted that he pursued the ultimate crime and even thought of killing. His partner is the reasoning writer Yusukawa Yusu (Masataka Kubota). As an assistant, he will always be tolerant and help Homura, and the two work together to solve many cases. Mizuki Yamamoto, Makita Sports, Kyoko Hasegawa, and Mari Natsuki, who appeared in the previous game, will all appear, and many special guests will be added at the same time.