Ok, so you know how when we want to learn about something that happened a long time ago, we need to read about it in books and papers? Well, some really smart people at the University of Tokyo made a whole building that is just for studying and writing about history!
They're called the Historiographical Institute and they collect all kinds of documents and records from Japan's past. These are things like letters, diaries, and even old maps! Then, they use these things to help them figure out what happened in the past and why.
The people who work at the Historiographical Institute are kind of like detectives. They try to piece together all the clues from the past to figure out what really happened. They write a lot of papers and books so that other people can learn from what they found.
So, basically, the Historiographical Institute is a special place where smart people go to read old things and learn about what happened a long time ago in Japan. They then write about it so that everyone can know more about Japan's history.