With a sharp knife, cut the abdomen of the fish to open it up. Remove the guts and discard them. Rinse under cold water to clean the inside and remove any traces of blood. Once the fish is clean, cut into 2 inch pieces.
Sprinkle salt (or kobucha) and set aside for 10 minutes.
In a large frying pan, heat the oil on medium-high heat. Add the fish and cook both sides until brown and crisp. Wipe off any excess oil on the frying pan with a paper towel.
Add the Teriyaki Sauce. Shake the frying pan and coat the fish well with the sauce.
When the sauce gets thicken, add green onion. Shake the frying pan to mix well and transfer the fish to a serving plate. Drizzle the sauce over and serve immediately.
You can keep the leftovers in an airtight container and store in the refrigerator for up to 1-2 days.