To make the brine, mix together the water, 1/2 cup brown sugar, salt, 2 tablespoons ginger, onion, lemon, 5 cloves of garlic, and 1/2 cup teriyaki sauce in a large container. Add the pork tenderloin, cover, and refrigerate for 2 to 8 hours.
For the glaze, whisk together 1/2 cup teriyaki sauce, sweet and sour sauce, hoisin sauce, 4 cloves of garlic, 2 tablespoons ginger, brown sugar, and orange juice.
Prepare an outdoor grill for high heat.
Cook the pork tenderloin on the preheated grill until no longer pink in the center, 7 to 12 minutes per side. Remove the tenderloin from the grill and cover with foil; allow to rest for 10 minutes. To serve, brush with glaze, and cut into thin slices.
