Supreme (remove flesh sections from membrane) one grapefruit; set aside. Juice the other grapefruit. In a small bowl, combine grapefruit juice, yuzu juice and rice vinegar. Reserve and chill.
Combine ginger, ogo, onion, tomatoes, cucumber and grapefruit wedges. Reserve and chill. Combine prepared juices, vegetables and shrimp. Add Hawaiian chili pepper to desired heat. Arrange on a serving dish. Top with ahi; season with sea salt. Garnish with cilantro. Makes 4 servings.
Approximate Nutrient Analysis per serving (based on 8 shrimp = 0.5 pound with not including salt to taste):
170 calories, 1.5 g fat, 0 g saturated fat, 135 mg cholesterol, 600 mg sodium, 17 g carbohydrate, 2 g fiber, 2 g sugar, 23 g protein
