It is entirely possible that you may never have heard of Isao Takahata's 1988 masterpiece. For all the increasing visibility of Japanese animation in "the West", Grave of the Fireflies has yet to gather a populist following here. Yet one could, without dallying too much in hyperbole, argue that it is one of the greatest animations ever released and among the most moving of all anti-war films (though the director bristles slightly at that description). Those who have yet to see it are to be envied a chance to catch the anime first on the big screen.

Grave of the Fireflies dallies in difficult, uncomfortable territory: the wretched last days of the second World War in Japan. We begin with a young boy named Seita dying of starvation some time after the surrender. A passerby roots through his meagre possessions and comes across a tin harbouring ashes. When he throws the contents away, the spirits of Seita and Setsuko, his sister, rise to lead us through the main body of the film. It is a grim tale. When their mother is killed in an air raid, they move in with an unsympathetic aunt and ultimately end up foraging for food in the unwelcoming wasteland.

Films about children in war have rarely been so ruthless to their subjects. Fireflies is, of course, given its genre, a great deal more lyrical and at home to mysticism than a withering masterpiece such as Elem Kimov's Come and See . The hints of an afterlife allow a smidgeon of hope that the Russian picture could never contemplate.

And yet it is, in its way, every bit as savage. We have become so used to animation being used to sentimental ends that, a quarter of a century after its first release, Grave of the Fireflies still manages to sideswipe your expectations.

Takahata claims the film has “no message”. With respect to the director, the film does have a message, but it is so pure and uncomplicated you could easily take it for granted: we really should be nicer to one another. A film for the ages.