Tonkatsu sauce is a thick, savory condiment commonly used in Japanese cuisine, particularly as a dipping sauce for tonkatsu, which is breaded and deep-fried pork cutlet. The sauce is made from a blend of ingredients, including soy sauce, Worcestershire sauce, sugar, and various spices, giving it a unique sweet and tangy flavor. This sauce is not only popular for tonkatsu but can also be used with other fried foods, such as croquettes and tempura. Its rich taste enhances the overall dining experience, making it a staple in many Japanese households and restaurants.