Shaku Nihongi is a book that was written a really long time ago in ancient Japan. It tells us about the history and culture of Japan from a very long time ago.
Imagine you have a diary where you write all the things you did, saw and heard every day. This book is like a very old diary for Japan. It helps us understand what life was like in Japan a long time ago.
The book is written in special Japanese language that's hard to understand for many people today. So, we have to use special tools and techniques to help us understand what it says.
It helps us know about the important events and festivals that people celebrated a long long time ago. It also tells us about the people who ruled Japan and how they did things.
Overall, Shaku Nihongi is a really important book for understanding the history of Japan and people from the past.