Combine starch, sugar, salt and 1/4 of the water. Whisk well to combine and dissolve all the starch. Cook in a medium sized sauce pan on low heat, mixing constantly with a rubber spatula. The mixture will thicken and get clear. Transfer to a pan that has been lightly coated with water. Let chill at room temperature. Do not refrigerate. Once thoroughly cooled, transfer to a cutting board and cut into chunks, wetting your knife as you go. Serve with kuromitsu or maple syrup, kinkako and fruit if you would like. Easy peasy!