Umi budo, also known as 'sea grapes' or 'grape seaweed', is a unique and delicious Japanese marine ingredient. it is a seaweed that grows in the warm waters of certain regions of Japan.umi budo have a distinctive appearance, resembling small translucent green bubbles, often described as resembling bunches of grapes. Their texture is slightly crunchy, with a fresh, slightly salty mouthfeel.