Combine the ground pork, garlic powder, green onions, salt, pepper, sesame oil and sugar in a bowl until well distributed.
Cover the bowl with a plastic wrap and let it rest for at least an hour the flavors to blend or place in the fridge overnight.
Take a spoonful of the filling and place it in the middle of a wrapper. Wet the edges of the wrapper with water to make them stick together. Fold it in half and pinch the center top part of the wrapper together and form the gyoza by pleating the side of the wrapper facing up. (See photos).
In a non-stick skillet or frying pan, heat oil over medium-high heat. Place the gyoza in a single layer, flat side down. Fry it for about 3-5 minutes or until the bottom turns golden brown.
Pour ¼ cup of water into the pan and cover with the lid to create steam. Cook for another 3 minutes or until most of the liquids are gone.
Remove the lid to let the remaining liquid evaporate then add a teaspoon of sesame oil and cook uncovered for another few minutes until the bottom is crisp.
Transfer cooked gyoza into a serving dish.
To make the dipping sauce, just combine all ingredients in a small bowl and stir until sugar is dissolved.