1. In a large mixing bowl, pour cold water, add and combine together the unflavoured gelatin packets. Mix until there are no lumps. Set this bowl aside.
2. In a pot over high heat, pour water and bring it to a boil.
3. Once it starts boiling, pour in the Sempio rice vinegar, add honey and mix well until the honey is dissolved. Bring this liquid to a rolling boil.
4. Once it starts to boil, switch off the gas and pour the liquid into the gelatin mixture and mix until the gelatin dissolves.
5. Take a flat-bottomed glass container and pour the dissolved gelatin mixture into it. Place this container in the refrigerator for about 5 hours or until the mixture becomes firm.
6. Once done, remove the container and using a sharp knife, make a cut around the edges to easily remove the gelatin.
7. Turn the container upside down over a plate or a chopping board and gently remove it.
8. Using a sharp knife, cut the gelatin into cubes or any other desired shape.
9. Serve these rice wine vinegar gelatin cubes in a bowl.
As an alternative, you can use some kind of fruit juice. In that case, replace all of the water in the first and third steps with the juice of your choice.
If you are using fruit juice instead of the drinking vinegar, you might want to reduce the amount of honey or sugar since the juice is already sweet.