Soak kelp (seaweed) with water.
Puree pineapple with your food processor or blender.
In a sauce pan, add sugar over low heat and some of the soaked water. Stirring frequently to avoid burn.
When sugar is melting and caramelizing, pour in the soaked seaweed (along with the rest of water) and puree pineapple.
Stir to mix and bring to boil over medium.
When boil, reduce to low and simmering for 10 minute.
Strain and discard all the solid. Continue to simmer the liquid with soy sauce to reduce it.
Adjust with salt to desired saltiness in case your soy sauce is the less sodium type. Use this as raw fish sauce substitution or mix with crushed garlic, chili, lime for the dipping version.