On the last possible day they could do it without breaking an agreement Stalin made in Tehran in 1943, the Soviet Union declared war on Japan. This was August 9th, the day the US dropped the second atomic bomb on Nagasaki. About three weeks later, Japan surrendered, and the Soviets had visions of occupying (and doubtless annexing or splitting Germany-style) some of the Japanese Islands, like Hokkaido. They were largely thwarted in their ambitions.
Giovanni's Island, an animated film out of Japan, tells the tale of one place where they weren't.
Shikotan is a small island north of Hokkaido, and our story begins in 1945 after the surrender, and young Junpei and Kanta's grandfather is describing the depredations about to be visited upon them by the invading American horde. Hide yo' kids, hide yo' wife, kinda stuff.
Instead of the Americans, though, it's the Russians. And they steal everything. I presume they raped everything, too, but this is a kid's movie, so nothing of that sort is shown.
On the other hand Grave of the Fireflies is also a kid's movie, so keep that in mind going in. This is not quite at that level. If memory serves, Fireflies is near constant tragedy, whereas this has strong elements of the positive aspects of a "coming of age" story.
For example, the Russian commandant who takes over the island (and Junpei and Kanta's house) has a young daughter, Tanya, who evolves a relationship with Junpei. The Japanese and the Russian kids end up learning each others' folk songs. While Junpei's family lives in the adjoining stable to their old house, Tanya and the boys share a toy railroad track.
The railroad is the theme of the story: Giovanni's Island is a science-fiction story the boys father read to them, and they are named after the two main characters of that story. (Well, sorta: Junpei is as close as you can get to Giovanni. And Kanta is...Capone or something.) This story has to something to do with trains, and the boys are obsessed with them. (They've never seen one. They live on a rural island.)
Things take a turn for the worse when the Russians decide to clear the island of the pesky Japanese and the boys take it on themselves to find their captured father.
But it's a good story, strangely bittersweet, and very Japanese. (But not Studio Ghibli.)
The Boy approved.