Grate ginger until you have enough to fill 1/3 of a cup.
Pour lemon juice into a pitcher and add ginger. Stir and set aside.
Slice off one whole side from one of the mangoes and set aside.
Extract as much of the flesh of the rest of the mangoes as you can in the most efficient way you can and then place the mango flesh in a blender, top with a couple of tablespoons of water and then blend on the lowest setting on your blender. Leave in blender and set aside.
Add water and agave to lemon and ginger and stir.
Taste to check intensity of ginger, if you prefer a strong ginger taste, let your ingredients stand for 15-30 mins.
Once you have your desired ginger intensity, pour ingredients into blender with mango puree.
Blend on lowest setting until ingredients are fully mixed.
Slice set aside mango and place on skewers.
To serve, pour your mango ginger lemonade over ice and garnish with a mango skewer.