Clean the ayu fish by scraping off the slime with a knife from tail to head. Rinse with water and pat dry with paper towels. Sprinkle both sides with salt.

Place cooking paper in a frying pan and arrange the ayu fish. Heat over medium heat until browned (2–3 minutes). Flip the fish, cover with a lid, and steam over low heat for 4–5 minutes until cooked through. While warm, flake the fish into large pieces, removing the head, bones, and innards.

Rinse the cooked rice with water to remove excess starch and drain.

In a pot, mix the broth ingredients (water, sake, mirin, soy sauce, and dashi powder) and heat over medium heat. Once boiling, add the rice and stir. Bring to a boil again, then add the flaked ayu fish on top. Cover and simmer over low heat for 3–4 minutes.