Shoyu is a type of soy sauce that originates from Japan. It is made by fermenting soybeans, wheat, salt, and water, resulting in a rich, savory flavor. Shoyu is commonly used in Japanese cuisine for seasoning and enhancing dishes like sushi, sashimi, and stir-fries. There are different varieties of shoyu, including koikuchi, which is the most common, and usukuchi, a lighter version. Each type has its unique taste and color, making them suitable for various culinary applications. Shoyu is also a key ingredient in marinades and dipping sauces, adding depth to many recipes.