Preheat oven to 350 degrees F (175 degrees C). Grease a muffin tin.
Beat cake mix, water, eggs, and oil in a large bowl with an electric mixer until combined. Pour batter into the prepared tin.
Bake in the preheated oven until a toothpick inserted into the center comes out clean, 12 to 17 minutes. Let cupcakes cool in the tin, about 20 minutes.
Transfer cupcakes to a flat work surface. Trim each cupcake into the shape of a round sushi roll or rectangular maki. Coat the cake rolls with icing and shredded coconut. Top with gum drops, dried mango, dried ginger, and sprinkles. Wrap fruit rolls around the cake rolls.