Teriyaki Grilled Shrimp Skewers

Sauce:

• 1/3 cup water
• 2 tablespoons soy sauce
• 2 tablespoons brown sugar
• 1 teaspoon honey
• 1 teaspoon grated fresh garlic
• 1 teaspoon grated fresh ginger
• 1 pound jumbo shrimp
• 1/2 fresh pineapple, cored and cut into 1 ½-inch pieces
• skewers
• 2 tablespoons minced fresh cilantro (Optional)
• 1 tablespoon toasted sesame seeds (Optional)