What would you do if, while sorting through your late father’s possessions in the family home, stumbled upon a decades-old tape recording of yourself – just a small child – that incriminated you in a major unsolved crime? What would you do? Who would you tell?

The Voice of Sin, a 2020 Japanese crime drama, is partly inspired by true events. It follows Toshiya Sone (Gen Hoshino), a Kyoto tailor who discovers such a tape. It contains his own childhood voice giving directions to a ransom drop-off in a notorious extortion case from the early 1980s. It sets Sone on a journey to discover the circumstances of the recording, and who in his family was part of a criminal gang – never caught – who threatened to poison the stocks of two candy manufacturers.

At the same time, Osaka arts reporter Eiji Akutsu (Shun Ogiri) is reassigned to write about the anniversary of the same unsolved case. When he stumbles upon new evidence, it sets him on a path to actually uncovering the guilty parties. Before long Akutsu realises he is not the only man tracking the case, and instead he is one of two people searching for answers for completely different reasons.

This is a slow, measured film, one that takes a forensic approach to historical crimes. Each witness is identified by on-screen captions. Testimony leads both protagonists on a path from one person to another, slowly filling the gaps and building a collective picture of the past. It is done with a focus on character and a strong sense of narrative. This sort of flashback-heavy drama could easily drag or stumble, but a good screenplay and excellent performances (including former Lady Snowblood star Meiko Kaji) instead make it utterly engrossing.

A general knowledge of crime and justice in Japanese society is important. This story could not be told in another cultural contexts. Families regularly share the shame of one member’s crimes, suffering social consequences for their actions despite not being guilty themselves. For a professional tailor like Sone, being linked to the extortion case would destroy his reputation and business. Thus it is logical for him to hunt down the facts of what happened, in order to keep them hidden. A journalist like Akutsu could ruin everything. It gives the interactions between the two men an extra-strong sense of conflict that underlies their conversations.

This is a smart, sad, and engrossing crime drama. The casting of major stars Shun Ogiri and Gen Hoshino ensure a powerfully-played centre, and the often-complex web of identities and events is laid out meticulously and clearly. For director Nobuhiro Doi, it is a laudable achievement. At the 44th Japanese Academy Film Prize ceremony, it received six nominations and winning one (for the screenplay). They are accolades that are well-deserved.