Blanch the sweet potato leaves. This is done by putting the leaves in boiling water. Let it stay for about 20 to 30 seconds. Remove the leaves and submerge in a bowl of cold water for 30 seconds, and let dry.
In a large bowl, combine sweet potato leaves, tomatoes, ginger, onion, sugar, salt, pepper, and vinegar. Gently toss until all the ingredients are distributed.