Steep the green tea bags in hot water for 10 minutes. Discard bags.
Stir in the sugar and pour the mixture into a 9 by 9 inch baking pan. Cover and put into the freezer.
After 1 hour, using a fork, scrape the frozen top layer. Scrape and break frozen blocks into pieces. Continue to scrape every 15 to 20 minutes until the granita has a fluffy, snowy consistency – about 2 hours. Eat immediately or keep for 3 days, scraping every so often.
For the best results, use plain green tea, without any additional flavorings. Add sugar to taste, but go easy on it.