Ponzu is a seasoning made from citrus fruit juice mixed with vinegar. It primarily uses juices from yuzu, lemon, sour orange, and green tangerine, giving it a refreshing flavor. Mixing ponzu with soy sauce is called "ponzu shoyu" or "ponzu soy sauce", but it's also simply referred to as ponzu. Typically, when people mention ponzu, they are most likely referring to the soy sauce mixed version. It's often used as a dipping sauce for shabu-shabu or hot pot dishes.