Synopsis

Shiota Takeshi’s acclaimed mystery novel “Voice of Sin,” has been adapted to film featuring the first-ever on-screen collaboration between Oguri Shun and Hoshino Gen. The story, inspired by Japan’s greatest unsolved crime of the Showa era, portrays two men whose lives are dramatically impacted by past events.
 
As the Heisei era draws to a close, newspaper reporter Akutsu Eiji (played by Oguri) is selected for a special investigative team pursuing Japan’s greatest unsolved case. He spends his days conducting extensive research based on remaining evidence, seeking the truth behind this 30-year-old mystery. Akutsu becomes particularly fixated on the fact that the criminal group used recordings of three children’s voices in their threatening tapes.

Meanwhile in Kyoto, tailor Sone Toshiya (portrayed by Hoshino) discovers a cassette tape among his late father’s belongings. Playing it out of curiosity, he is shocked to hear his own childhood voice—the same voice used on threatening tapes by criminal perpetrators who terrorized multiple companies and shook the nation over three decades ago in Japan’s most infamous unsolved case.