Misshitsu Kyouran Jidai no Satsujin - Zekkai no Kotou to Nanatsu no Torikku (Associated Names)

In the winter of three years ago, the first locked room mu*der in Japanese history was committed. All of the evidence pointed to the defendant. It was certain they were guilty. And yet, they were found innocent and released. Why? Because the crime scene was a perfect locked room no one from the police or…