For 2 portions, put 5-6 lychees and 5-6 mint leaves in a jar. Squeeze the juice of 1 lemon and muddle lightly.
Put equal amounts of muddled lychee mixture into 2 serving glasses. Add few ice cubes, 1 lemon slice, 1 tablespoon sugar syrup into each glass and fill them up with drinking soda and stir well. Make more lemonade similarly.
Garnish each glass with 2-3 mint leaves and serve immediately.