China
Sudden
Under a canopy, someone thinking with a brush in their mouth has a sudden thought, and uses the brush to write the word "China". Thus, China was born.
とう
から
None
Believe it or not, this sudden invention of China happened in とうきょう. Well, it wasn't とうきょう yet. And it was a traveling Chinese person who did it. But you know legends, they're just all over the place.