In a medium bowl, toss the fruit in the sugar to coat. Grill over medium heat, until a golden crust begins to form on the fruit, about 3 to 4 minutes per side.
In another medium bowl, mix together the mint, lemon juice, and simple syrup. Arrange the fruit on a serving platter, drizzle the mint syrup over top, and serve.
In a saucepan, combine water and sugar over medium heat. Bring to a boil, then reduce heat and simmer for 5 minutes, or until the sugar has dissolved. Take pan off heat and cool the syrup before using. Any extra cooled syrup can be refrigerated in an airtight container for up to 2 weeks.