Let Kombu submerge in water in a large bowl and rehydrate for 15 minutes.
When Kombu becomes soft, take it out from the water and pat dry. Slice into 2" long, thin strips.
Put 1/2 cup water and vinegar along with cut Kombu in a small pot. Cook at medium low heat for 10 minutes. Then add all the seasonings, and cook until the liquid is gone. Add sesame seeds and mix.