The Kai Highway is a large field area in the game Mystical Ninja: Staring Goemon. It is situated between Oedo Town and Mt. Fuji. It has a coffee shop, and features standard enemies, like ball dolls and flying wolves. A Silver fortune doll is also in the area, lying to the right of the gate of Mt Fuji. A river flows through the area, of which two bridges cross to access different areas.
The area is actually the first area of the game which can be accessed after starting in Oedo Town. The Map of Japan is obtained in the coffee shop, which allows Goemon to view the areas he has allready visited. Once the Chain Pipe has been obtained, the area serves no other purpose.