Deka-Dance in a Circle

Summary
The Sket Dan tail first-year student Murao due to a request to investigate his appearance near the girls' changing rooms. While in the process of following him, the trio are accosted by Deka-chō, the head of the Deka Club. A fanatic for detective work and crime dramas who uses associated jargon, he proves to be aggravating and overbearing and decides to take control of the investigation. Suddenly, the foursome notice that Murao is also following someone - a girl from the Deka Club named Ringo. She, in turn, is acting on Deka-chō's orders and following Tsubaki in order to discern the Student Council's weakness... and Tsubaki is following Deka-chō due to rumors that the Deka Club viewed the student council as their enemy. It turns out that the chain of people tailing others is forming a complete circle, and it is all Deka-chō's fault.