Boil the sago. Fill a large pot with water and bring it to a boil. Add the sago and cook it according to package instructions. Let the sago rest for 20 minutes. Strain and rinse the pearls. Set them aside.
Brew the tea. Add the water to a large mug. Place the tea bag inside. Cover the mug and let the tea steep for 15 minutes. Remove and discard the tea bag.
Make the arnibal syrup. Add the dark brown sugar, tea, and vanilla extract to a small pot over low heat. Stir constantly and bring the mixture to a boil. Immediately reduce the heat and let the mixture simmer for 11-14 minutes or until the sugar is dissolved and the syrup has thickened. Remove it from the heat and set it aside.
Heat the tofu. Place the tofu in a microwave-safe container and microwave it for 2-4 minutes.
Assemble it. Cut the tofu into 1/2" slices. It doesn't really matter what size they are. Scoop them into a serving glass or bowl. Add sago pearls on top to taste. Pour in 4-6 tablespoons of arnibal syrup to taste. Top with coconut milk to taste.