Peel and chop 4 ripe kiwis and 1/2 pineapple into small pieces.
In a blender, add the chopped kiwi and pineapple pieces, 1/4 cup of sugar (adjust according to taste), and 1 tablespoon of lemon juice. Blend until smooth.
Add 2 cups of crushed ice to the blender and blend again until you achieve a slushie consistency.
Pour the slushie mixture into glasses and garnish with a slice of kiwi or pineapple, if desired. Serve immediately.