To brine shrimp, combine water, salt, sugar, and Kikkoman Soy Sauce in a large bowl, stirring to dissolve salt and sugar. Submerge 2 pounds of peeled and deveined shrimp in the brine. Brine for 1 hour.
Preheat oven to 400 degrees F (200 degrees C).
Rinse shrimp. Place on a rimmed baking sheet in a single layer. Roast shrimp until done, 6 to 8 minutes.
Whisk lemon juice, soy sauce, sesame oil, cayenne pepper, and garlic in a large bowl. Add peppers, cilantro, and shrimp; toss to coat.
