Add the soy sauce, Worcestershire sauce, oyster sauce, rice vinegar, tomato sauce (or ketchup), raw sugar, hoisin sauce, ginger and Japanese 7 Spice powder into a small bowl and mix well.
4 tbsp soy sauce, 2 tbsp Worcestershire sauce, 2 tbsp oyster sauce, 1 tbsp rice wine vinegar, 1 tbsp tomato sauce / ketchup, 2 tsp raw sugar, 1 tsp hoisin sauce, 1/2 tsp ginger, pinch Japanese 7 Spice