The seaweed in this dish is kelp, commonly called konbu or kombu in Japanese, or haidai in Chinese. The ones I got are in the form of fresh, unsalted strands and are slightly crunchy in texture. You can purchase them dried also.
If you buy them fresh, you will need to rinse them many times to get rid of that slimy feel. Cut them into six inch strips. Remove the ends of the mung bean sprouts. Add both the bean sprouts to the marinade for at least an hour minimum, but I always do it overnight because the "spiciness" of the garlic really comes out and it lessens the sea smell of the seaweed. If you have kids who can't eat spice, you might prepare some of the seaweed omitting the garlic.
For 2/3 pounds of seaweed and 1/2 cup bean sprouts, you'll need for the marinade:
1/4 cup vinegar
1/4 cup water
4 cloves garlic, chopped
1/2 cup sugar
It's a different taste than that of wakame salad. I've tried adding sesame oil to this once but it didn't taste right in this combination. My kids love this salad because they find it different, but it provides another source of calcium for them, which I love.