Japan - United States of Odaiba

I was wandering around Odaiba last week when I came across some kind of big event. So I decided to check it out. Once I got closer I saw the event was called the "United States of Odaiba" and I thought cool, some kind of United States of America event. But once I looked around a bit, I realized that the event had absolutely nothing to do with America. It was a bit hard to tell what the even was for because other then the "United States of Odaiba" signs absolutely nothing was in English. Which was a little strange because usually there's at least some English signs around.

The one English sign I found. "You knock on a jumping door!"
The Japanese sure know how to have fun.