Gather all ingredients.
Mix together soy sauce, sake, mirin, and ginger in a large bowl until combined.
Add sliced pork; stir to coat. Cover the bowl and marinate for about 1 hour.
Heat oil in a large skillet or wok over high heat. Sauté pork in hot oil until browned and cooked through; discard marinade. An instant-read thermometer inserted into pork should read at least 145 degrees F (63 degrees C).
