In a 3.5 qt or larger pot add two cups of cold water and soak kelp for about one hour.
Scrub potatoes then puncture them with fork. This will help potatoes absorbs more flavor when cooking.
In a medium pot, bring water to boil then cook the pork for about one minute. Drain the water and rinse the pork with cold water.
Gently bring #1 to a simmer, take out the kelp and cut into pieces.
Add pork, sake, ginger, white part of green onions and kelp to #4. Turn the heat low and cover the pot and simmer for 30 minutes.
Add potato and sugar then cook for another 10 minutes.
Add carrots and daikon radish and cook for another 10 minutes.
Once the vegetables are soft, add ¼ cup of miso, mirin and green onions. Now take the cover off and turn the heat to medium and cook for about 5 minutes until liquid thickens a bit. Taste test and add more miso if necessary. Remove ginger piece and drizzle sesame oil. Let it rests for 10 minutes. Serve hot.