1Line a rimmed baking sheet with a kitchen towel or several layers of paper towels; set aside. Bring 2 cups white short-grain sushi rice, rinsed until water runs almost clear, 1 garlic clove, 1 whole star anise pod, 2 whole allspice, and 2½ cups cold water to a boil in a medium saucepan over medium-high. Reduce heat to low, cover pan, and cook until water is evaporated and rice is tender, 18–20 minutes. Remove from heat and let sit, covered, 10 minutes; discard garlic, star anise, and allspice.
2Meanwhile, cook ¼ cup coconut sugar or vegan granulated sugar, ¼ cup unseasoned rice vinegar, 1 Tbsp. grapeseed oil, and 1 tsp. sea salt in a small saucepan over medium heat, stirring to dissolve sugar. Let cool slightly.
3Meanwhile, place 2 cups ⅛" cubes watermelon (from about ¼ small watermelon) in a colander set over a bowl and sprinkle with 2 tsp. sea salt; toss to coat. Let sit 10–15 minutes, then drain off any liquid collected in bowl.
