Gather all ingredients and, if using strong hojicha instead of powder, brew it now; note that this recipe requires 2+ hours of cooling and chilling time.

In a saucepan, combine water (or strong hojicha) and kanten powder; whisk, bring to a boil over medium heat, then simmer on low for 2 minutes, whisking occasionally.

Remove from heat, add sugar and hojicha powder, then whisk until dissolved and fully incorporated without lumps.

Prepare a mold (like a nagashikan or baking pan) by rinsing it with water and shaking off excess, leaving it undried, to prevent sticking.

Pour the hot hojicha mixture into the mold and remove any surface bubbles using a butane torch or by scooping/popping them.

Allow the jelly to cool and solidify at room temperature for 45-60 minutes, then cover and refrigerate for at least 1 hour to chill.

For the topping, combine sweetened condensed milk and milk, mixing well and adjusting consistency/sweetness as desired; skip for vegan/vegetarian, or use kuromitsu.

Remove the chilled jelly from its mold, cut into ½-inch slabs, then sticks, and finally ½-inch cubes. Serve in individual dishes topped with the sweetened condensed milk mixture.

Store leftover jelly in an airtight container or covered in the refrigerator for up to 3 days; do not freeze.