I found this fascinating quote today:
Gyoza is originally a Chinese dish, which has become very popular across Japan. This recipe shows how to make the gyoza dough and the gyoza filling. The time consuming and difficult part of making of the dough can be skipped by buying pre-made dough pieces, which are available at some Japanese and Chinese grocery stores.foodrecipesworld.blogspot.com, Food Recipes Of The World
You should read the whole article.