Sprinkle sliced strawberries with sugar.
Let stand 30 minutes.
Mix 1/2 cup yogurt and strawberry-sugar mixture.
Spread about 4 tablespoons yogurt-strawberry mixture down center of each manicotti.
Fold sides over mixture.
Spoon 1 tablespoon remaining yogurt over each filled manicotti.
Place 1 whole strawberry on each dollop of yogurt.
Makes 4 to 8 servings.