Place dried shiitake in a bowl of warm water.

Place kombu in a pot and fill with the 4C water. Slowly bring to a boil. Just before the water starts to boil, remove Kombu.

Place chicken thighs in the broth and cook through. Remove the chicken and let it cool on a plate. Remove scum from the broth.

Remove skin from the chicken and de-bone. Reserve chicken pieces.

Pour katsuobushi into broth and bring back to boil for 30s. Turn off heat and let the katsuobushi sink to the bottom, then strain the broth.

Squeeze shiitake over bowl and cut off the stems. Reserve the shiitake. Pour the shiitake water into the pot of broth, being careful not to pour the liquid at the bottom which has all the dirt. Add the soy sauce, sake, and sea salt to the broth.

Bring the broth back to boil and blanch the greens. Remove the greens and reserve.

Peel the carrot and cut 1/4in slices. Use sakura flower cutter to make the flower shapes from each slice. Place the flower carrots in the broth and simmer for 5min. Remove the carrots and reserve.

Cut the kamoboko into 1/4in slices and place them into the broth. Add the shiitake into the broth.

Warm up the mochi by following the package directions.

To serve: pour 3 ladles of broth into bowl. Place mochi in the bowl. Arrange kamaboko, shiitake, chicken, greens, and carrot flowers around the mochi. Top with chopped green onion.