Put another way: Yes, the damage and devastation caused by the atom bombs was absolutely awful, and it can seem rather ironic that one of the targeted cities was Nagasaki -- with its significant Japanese Christian population and history, never mind people (like Koji) who loved Western classical music and such. But those weapons of mass destruction didn't just drop out of the sky for no reason! And Yoji Yamada (born in 1931, and consequently one of the few active filmmakers today who lived through the Second World War) really would have done more of a service to the film's audience -- local Japanese or otherwise -- and probably also made the movie better by acknowledging that.