Prepare half-round silicone chocolate molds or small sake cups.

Prepare two different sized small round objects for cutouts.

Combine water, Calpico concentrate, and powdered kanten in a small pan.

Heat through while mixing slowly until almost boiling.

Reduce heat to low and simmer for 1 minute to dissolve the kanten.

Take 40 ml of the jelly liquid out of the pan and divide into two 20 ml portions.

Keep remaining jelly liquid in a hot water bath to prevent solidification.

Prepare two small flat plates.

Add black food coloring to one plate and blue (or another color) food coloring to the other.

Add 20 ml of reserved jelly liquid to each plate and mix rapidly.

Chill the colored jelly plates, uncovered, in the refrigerator for about 3 minutes.

Cut out iris and pupil parts using the different sized cutouts (black for pupil, colored for iris).

Place black circles in the bottom of the molds and press down lightly.

Add colored circles on top and press lightly to secure.

Add a small amount of white jelly liquid to each mold and wait 3 minutes.

Add the rest of the white Calpico jelly liquid.

Chill and firm up the jellies in the refrigerator.

Pour grape juice into small tasting glasses.

Float an eyeball jelly on top of each glass.