In a shallow large bowl, whisk water, soy sauce, vinegar, ginger, garlic, brown sugar, honey, and cornstarch mixture.
Arrange salmon in marinade bowl and turn to evenly coat. Allow salmon to marinate 30 minutes.
Preheat an outdoor grill to medium-high heat OR prepare a large nonstick pan to use indoors on stovetop by greasing well. Remove salmon from marinade (do not discard marinade) and grill on a sheet of nonstick aluminum foil on outdoor grill or on stovetop until salmon registers 125-130F.
Pour teriyaki marinade into a small pan and bring to a simmer over medium heat, stirring occasionally until thickened. Set aside for a moment.
Divide rice between 4 serving bowls and arrange a piece of salmon in each bowl. Drizzle warm teriyaki sauce over salmon.
Spoon mango slaw into bowls and garnish bowls with a drizzle of spicy mayo, sliced green onions, and sesame seeds. Serve immediately and enjoy!