Whisk together the sugar, corn syrup, soy sauce, sake, hoisin sauce, white miso, red miso, ginger root, garlic, shallot, and 3 tablespoons canola oil in a bowl until blended. Toss the fillets with the marinade, cover, and marinate in the refrigerator 4 to 6 hours.
Preheat oven to 350 degrees F (175 degrees C).
Remove the fillets from the marinade, and scrape off the excess. Scrape the marinade into a small saucepan and set aside. Heat the remaining 2 tablespoons of canola oil in a large, heavy cast iron skillet over high heat. Brown the fillets in the hot oil for 1 minute on each side, then place into the oven, and bake until the fish flakes easily with a fork, about 10 minutes.
While the fish is in the oven, bring the remaining marinade to a simmer over medium-high heat, then reduce heat to medium-low, and simmer for 10 minutes. Serve the sea bass accompanied by the miso sauce.
