Make sure you watch the episode before you read my notes, as they will spoil the episode. If you don't care about that, read on.
First of all, the story that Mr. Shinozaki tells is completely true: the friendship dolls really were exchanged by Japanese and American children prior to World War II. When the war happened American things were rounded up and purged. The dolls were unfortunate victims, and many of them really were used for target practice, stabbed with spears, burned, or cut with swords. Some people had the foresight to know that wars do end and times do change, and some dolls managed to be hidden away. Out of 12,000 dolls sent to Japan, a mere 331 survive today, and they are on display in various places. In the United States, many Japanese dolls have been discovered, recovered, and placed on display, but many more are still lost.
If you happen to have a grandparent or great grandparent with a strange doll from Japan in or around one of the cities from the article, you might want to look into whether or not it's one of the missing dolls, because they're an interesting relic of history.
It's also worth noting that the song that Reiko sings at the end is a real song. It was written by Ujo Noguchi, who composed numerous Japanese children's songs.
The episode itself is OK, but the historical aspect of it is quite interesting. Susumu Takaku, usually known for creepy things, writes this one.
Torrent Link: https://www.nyaa.se/?page=view&tid=870671