Cut tuna into 1-inch cubes. Place in a large plastic bag. Add soy sauce, water, snipped green onion tops or chives, and ginger. Seal bag and turn gently to coat cubes. Let stand at room temperature for 20 minutes. Drain, reserving marinade.
Thread tuna, pineapple, sweet pepper, and green onion pieces onto skewers. Grill kabobs, uncovered, directly over medium coals for 6 to 9 minutes or until tuna just flakes easily with a fork, turning once.
Meanwhile, bring reserved marinade to boiling; strain. Discard any solids. Stir honey into hot marinade. Brush tuna, fruit, and vegetables generously with honey-soy mixture just before serving. Makes 4 servings.