I regularly go to Tosa and the food has never failed them. It tastes like what you would be served in Japan. The overall atmosphear could be improved (a bit quiet sometimes) but it is the quality of the food that makes a difference. Many native Japanese people come to this place, so it is always a good sign. Staff is not always Japanese-speaking, but definitely polite and helpful.
The best dishes I have tried are salmon teriyaki, agedashi tofu, all the yakitori (especially the pepper ones), seaweed salad and sesame dressing.
Formerly Nanking, Tosa serves delicious Japanese cuisine, including sashimi, tempura and a selection of char-grills. The restaurant has a welcoming atmosphere and the staff and warm and efficient.