Combine soy sauce and cornstarch in a small saucepan, stirring with a whisk. Add brown sugar, mirin, and lemon juice; bring to a boil. Cook 1 minute or until thickened. Sprinkle chicken with salt and pepper. Heat a large ovenproof skillet over medium-high heat. Add canola oil to pan; swirl to coat. Add chicken to pan; cook 4 minutes. Turn; drizzle 1 tablespoon soy sauce mixture over chicken.