以日本2010年在全国警察本部设立的未解决事件专职班为原型,对体力和柔术非常自信的热血刑警矢代,擅长文书解读的高智商刑警鸣海,她们属于警视厅搜查一课“特命搜查对策室”第六系文书解读系,负责未解决事件的文书搜查,利用文字为切入点解决未解决案件。After waking up from a month-long coma due to injuries sustained in a reckless, heated investigation, detective Yashiro Tomo quickly returns to work at the Tokyo Metropolitan Police Department. She is ordered to transfer from the First Investigative Division's Violent Crimes Unit to the Sixth Special Investigations Unit. Located in the basement, it is in charge of deciphering documents of unsolved cases. Despite Tomo's bewilderment, she begins work in her new postalong with a brusque senior detective Narumi Risa who is called the expert of document deciphering for her unusual ability to predict the personality and thoughts of a writer from writings. However, the reality is that this kind of work is nothing more than that of a "storekeeper" of investigation materials