Soak tapioca pearls in water for about a hour. Cut grass jelly into ¼ inch cubes. Chill in the fridge.
Bring 4 cups (960ml) water in a pot to boil. Add soaked tapioca pearls. Reduce heat and simmer for 7 minutes. Do not cover pot. Tapioca pearls should be ready when they turn translucent. Remove, drain and rinse with cold water.
Scoop ¼ cup tapioca pearls into a glass. Top with ¼ cup grass jelly. Drizzle 2 tablespoons (or to taste) each of maple syrup and half and half onto grass jelly.
If grass jelly clumps together, rinse with warm water to break up clumps.