Ok kiddo, have you ever been to a museum before? You know, where they have exhibits of cool and interesting things from the past. Well, the National Museum of Japanese History is a big museum in Japan where they keep lots of important things that tell us about how people used to live in Japan a long time ago.
Now, in this museum they have something like a little magazine called the Bulletin. This Bulletin is like a special book that comes out every year and talks about all the new information that they have learned about the things in the museum. It's kind of like a sneak peek into all the cool stuff that the museum people have been working on.
So imagine, for example, that they found a really old sword in one of the museum's exhibits. The museum workers would study this sword to learn more about it. They would measure it, look at it closely, and do some research to try and figure out when it was made, who may have used it, and what kind of battles it may have been a part of.
Then, once they knew all this new information about the sword, they would write it all down in the Bulletin so other people who are interested could learn about it too.
So the Bulletin is like a special book that tells us all about the new things that the people working at the museum have learned about the cool stuff they have there. It's like a really cool history lesson!