Prepare the fruit: Peel and chop the kiwis into small pieces.
Roll the lime on the counter with firm pressure before cutting to extract more juice.
Muddle the flavors: In a cocktail shaker, add the kiwi chunks, mint leaves, and the juice from one lime (about 2 tablespoons).
Gently muddle until the kiwi is crushed and releases its juice.
Add sweetener: Pour in the simple syrup or honey and stir to combine with the muddled mixture.
Strain the mixture: Add ice to the shaker, cover, and shake for 10-15 seconds. Strain into two highball glasses filled halfway with ice.
Finish the drink: Top each glass with soda water (about 1 cup per glass).
Stir gently to combine the flavors without losing carbonation.
Garnish and serve: Add a slice of kiwi, a lime wheel, and a sprig of mint to each glass. Serve immediately while bubbles are fresh.