Unsolved Cases: The Scarlet Signal

Tomo Yashiro (played by Haru), a passionate detective who belongs to the 6th department of the "Special Investigation Countermeasures Room" of the Metropolitan Police Department's Investigation Division 1, visited the Kyoto Prefectural Police together with his high-IQ senior Narumi Risa (played by Suzuki Kyoka) who is good at text interpretation and director Shinji Soka (played by Kenichi Endo). Three days ago, a strange incident occurred in Kyoto. On the body of the deceased coffee shop owner Yusuke Takemura, the word "male" written with three Chinese characters connected together in red ink was found. Strangely, two people in the IT industry were killed one after another in Tokyo five years ago, and the words "bug" and "pin" were left in red ink at their respective sites. The case remains unsolved to this day. Tomo and Risa noticed that what was left at the scene of the incident were all three Chinese characters connected together in the shape of "pin". They believe it is likely that the murderer committed the crime again after five years. Although this conjecture was denied by their boss, Tomo and Risa still did not give up and continued to search for the truth of time. At this time, they learned that the murdered Takemura worked for the largest software company 4 or 5 years ago. Moreover, two days before Takemura was killed, he had a meeting with the president of the software company. In order to search for further clues, Peng and his colleagues went to the software company, but unexpectedly...