Go Shibata - NN-891102 (1999)

This film's cryptic title refers to the atomic bombing of Nagasaki (Nagasaki Nuclear 8 [August] 9 [the day] 11:02 [the time]). A 5-year-old boy survives the fateful blast and thinks that its sound has been captured on his father's tape recorder, only to become obsessed with reproducing it when the tape appears to be empty.
A first, the sound (or its absence) continues to traumatize him as he tries all manner of experiment to reproduce it, but gradually, as he grows older, it becomes oddly comforting. This emotionally powerful film features stunningly realistic flashback scenes that capture the look and feel of actual footage that could have been shot in 1940. NN-891102 was the first feature film by Go Shibata, who is perhaps better known for his 2004 film Late Bloomer.