Peel the kiwifruit, cut lengthwise into quarters, then thinly slice.
Reserve 8 slices for garnish.
To assemble the parfaits, divide the grapefruit sections among parfait glasses.
Spoon about 1 tablespoon yogurt over the grapefruit.
Sprinkle with about 2 tablespoons granola then top with another layer of yogurt and one-fourth of the kiwifruit.
Continue layering with the remaining yogurt, granola, and grapefruit.
Top with the reserved kiwifruit and garnish with the mint.