it doesn't make sense that Japan would be using ethanol in their gasoline fuels. They don't have land to devote to growing plants to make ethanol. They would have to import ethanol which would be expensive to do and make their gasoline even more expensive than it already is.

I beleive Enya added something to their special oil they require you to use in the engines. That is probably why it works with their special Enya glow plug. The glow plug may be a special one too.

The Japanese companies have made many engines that never really got exported to other countries. Heck I remember way back, circa 1975, when I was in the military and when I was in Japan and Okinawa, I bought several Japanese engines that never were sold in the USA. We were flying airplanes, running RC cars and airboats at the time. After coming back to the USA I discovered the engines were never sold over here. None of mine looked like or were compatible with what we had in the USA.