It is a kelp and bonito stock that is the basis of Japanese-style dashi. The umami of kombu is combined with the aroma of bonito stock and bonito extract to create a rich umami and aroma. Since ancient times, in Japan, the synergistic effect of the inosinic acid found in bonito and the glutamic acid found in kombu seaweed has created a synergistic effect that creates umami, an important sense of taste.