For dressing, combine Greek yogurt, orange juice concentrate, honey, and about 1 tablespoon reserved pineapple juice. Stir until well blended. Taste dressing and adjust; for sweeter dressing, add honey a teaspoon at a time. Add pineapple juice a tablespoon at a time for flavor or to loosen the dressing. Set aside.
Combine pineapple, blueberries, strawberries, mango, banana, and kiwi in a bowl. Add in dressing, and toss.
Place in a serving bowl or in individual bowls, garnish with mint leaves, if desired, and serve.