Make a pickling solution. Whisk together 1/4 cup vinegar, 1/4 cup sugar, and 1/4 cup water in a bowl.
Toss the mangoes, carrots, daikon, and cucumber in the pickling solution and chill for an hour.
Whisk together the vinaigrette. Combine the lime juice, fish sauce, 2 tablespoons sugar, chili, mint, and red onions in a bowl.
Drain the chopped vegetables from the pickling liquid and toss in the vinaigrette.
Top with shrimps and chopped peanuts.