Pour the water into a pot and dissolve the agar powder. Let it soak for about 5 minutes. Heat on low, stirring frequently. Once it starts to boil, add the granulated sugar and plain milk. Stir to combine, making sure to stir often to prevent the agar from clumping and to dissolve the sugar.

When it starts to boil again, divide the jelly into two parts. Set one part aside. Add the red syrup to the other part (you can adjust the color intensity to your liking, but be careful not to make it too sweet ☺). Turn off the heat and let it cool slightly. Pour into molds, alternating layers (for each layer, wait until the surface is slightly firm before adding the next layer). Let it set and refrigerate for extra deliciousness.