There are some films you watch and think that they are very good indeed, but you then more or less forget about them a few days later. Others stay with you forever, etched on your memory. Grave of the Fireflies is one of the latter kind for me. I had heard that it was a very depressing film, but actually, I think it's one of the most beautiful films I've ever seen. That isn't to say it isn't sad — if you sit through the whole film without crying or at least feeling very moved, I would be amazed (and secretly suspect that you have no compassion for others).

Grave of the Fireflies (Hotaru no haka) is a Japanese animated film set in the Second World War, and is about two siblings: Seita (about 14 years old), and his 4 year old sister Setsuko. They are left on their own, homeless, after an American bombing raid on their town, and the film is really the story of their relationship and the way in which Seita tries to protect and care for his sister.

There's the spoiler of all spoilers in the first few minutes of the film, but in a way that sets up a kind of happy-sad ending for the film at the start, and you are no longer tense, wondering what is going to happen, but just sit back and watch how it happens.

The animation itself is gorgeous and quite realistic (no huge-eyed animé munchkins here), but the characterisation of the children is even more impressive. They act exactly like real children of their age, and that makes it even more heartbreaking. I loved the way that Setsuko swung her legs happily while sitting on a chair or bench or crouched down to inspect ants on the ground. Similarly, Seita is every inch a teenage boy, albeit one who shows incredible tenderness towards his little sister. At several points throughout the film, Seita opens a tin of fruit sweets for Setsuko. It's such a simple thing, but she adores the sweets and her little fingers can't open the tin, so it's the perfect symbol of his love for her. Actually, just thinking about those scenes again brings a lump to my throat now.

Despite having a rather tragic theme, Grave of the Fireflies manages to steer a very delicate line, and never stoops to exploitative horror (though it is frank about the results of war), nor does it ever resort to sentimentality. Difficult scenes are handled very sensitively and the emotion comes from small details or juxtapositions, rather than dialogue or from either of the characters crying.

I could pick out many wonderful scenes (burned on my memory after only one viewing), but I will mention one that particularly struck me. It is the first night that Seita and Setsuko spend alone in an old bomb shelter that they have made their home. Setsuko has already fallen asleep, but Seita is lying awake. You can see that after all the activity and even excitement of settling in to their new home, he suddenly feels the full responsibility and loneliness of his position. He may try to be a big tough man, but he's only 14 and he misses his parents and his home and feels very alone. Seeking comfort, he rolls over to hug Setsuko, but she sleepily and grumpily pushes him away and tells him to get off her, so he rolls back and curls up.

That — and several other scenes — broke my heart.