ELI5: Explain Like I'm 5

China–Japan relations

China and Japan are two big countries that are very close to each other geographically. Sometimes they get along well and sometimes they have problems. Imagine if you have a friend who sometimes plays with you and sometimes fights with you – that's how China and Japan are like.

A long time ago, Japan used to be friends with China and even copied a lot of Chinese things like writing and culture. But then Japan wanted to be more powerful and took over some parts of China during World War II, which made China very angry. After the war, Japan apologized to China and the two countries agreed to be friends again.

However, sometimes China and Japan still have arguments. One reason is because they both want control over some little islands in the ocean called the Diaoyu Islands (China calls them the Diaoyu Dao and Japan calls them the Senkaku Islands). They both say that the islands are theirs and they have even sent ships and planes to patrol around them. The disagreement makes both countries upset with each other.

Another problem is about how Japan remembers what happened in World War II. China thinks that Japan should remember and apologize for what they did, and make sure that they don't do it again. Japan has apologized before, but some people in China believe that they haven't apologized enough.

So, in short, China and Japan have a complicated relationship. They both want to be friends, but sometimes they disagree on things and argue.