If you loved Postcard, try Children of Hiroshima
A bridge between a film you've already seen and one most people haven't. Here's what they share, and what the second one does that the first one doesn't.
What they share
Both films are directed by Kaneto Shindō, and they sit in Drama / War territory. If that's the register that drew you to Postcard, the second film will land in a comparable space — through a different lens.
What Children of Hiroshima is
You teach in a school near Hiroshima and then face the aftermath of the atomic bomb. The film leaves viewers with a sense of devastation.

