Steep Sakura tea for about 5 minutes in hot water. Set aside and let chill down.
Add Grenadine syrup to tea mixture stir together and place in a tupperware container and place in the freezer. (If diabetic, do not use grenadine syrup. Maple Groves Farms makes a great little diabetic red raspberry syrup that would be a nice alternative here) Adjust your addition of grenadine to your desired taste. I do not like my desserts too sweet.
About every half hour, scrape the ice mixture with a fork to keep it from freezing like an ice block. It should look like the consistency of snow.
Make the coconut syrup: In a small sauce pan add coconut milk and sugar (or diabetic sugar alternative) and cook over low heat for about 5- 8 minutes or until it is thick and creamy. (This will make extra coconut syrup and let me tell you this is fantastic on top of your tropical pancakes in the morning so that is why I made a bigger batch) You could reduce amounts of coconut milk and sugar by half, if you wish. I used white granulated sugar as I wanted a pure white glaze but you can use sugar alternatives such as agave but it makes your glaze a beige color but it tastes lovely. (If diabetic substitute with a sugar alternative of choice) Adjust sugar for your level of desired sweetness. I do not like my desserts super sweet.
Flake the sakura grenadine granita with a fork, one last time, and scoop into the glasses. Drizzle with sweetened coconut cream and top with fresh grated coconut. For the adults you can substitute a drizzle of umeshu (plum) liquor for the sweetened coconut cream. Enjoy!