Okay kiddo, so a long time ago, Japan was friends with China. They used to exchange lots of things like ideas, cultures, and products. And sometimes, important Japanese people called "missions" would go on long trips to visit China and learn from them.
These missions were like really big field trips, but with really important people. They would travel all the way from Japan to China, which was very far away and took a long time to get there.
Once they arrived in China, they would meet with important Chinese people and learn about their customs and ideas. This helped the Japanese people understand China better and make friends with them.
But sometimes, these missions didn't always go very well. Sometimes there were misunderstandings or arguments between the Japanese and Chinese people. And sometimes the Japanese missions would bring along lots of gifts to impress the Chinese people, but the Chinese people didn't always like them.
Overall, these Japanese missions to Imperial China were a way for the two countries to learn from each other and become friends. And even though sometimes things didn't go perfectly, it's still an important part of their history and relationship.