1. To prepare the daikon, cut 4 round slices, each 3.5 cm / 1.4 in. thick. Peel the thick skin. With a knife, make shallow cross-scoring** about a quarter of the depth of the slice (see photo). Round off edges of each slice and boil in enough water to cover the daikon over low-medium heat for 40 minutes, until tender. Allow to cool and then rinse. Drain and pat dry with paper towel.
2. Cut the mizuna into 3 cm / 1.2 in. lengths and set aside.
3. Place the simmering liquid ingredients in a saucepan. Add the daikon slices and cover with a drop-lid or parchment paper. Cook for 40 minutes over low heat.
4. Combine the tsukune ingredients in a bowl, mix and knead well. Form 12 balls using two wet tablespoons; this will make it easier to form the balls. Add the meatballs to the simmering liquid in the saucepan and simmer for 5 minutes over low-medium heat. Skim off the froth, which is aku.
5. Pour 120 ml / 1/2 C of the simmered liquid into another saucepan; add the mizuna and parboil, then remove.
6. Place the daikon, tsukune and mizuna in individual bowls. Pour simmering liquid over the ingredients and garnish with slivers of yuzu peel.

* Use rice water if available. This is water used to rinse rice prior to cooking. Rice water extracts unsavory smell, resulting in a more refined taste, and is used for parboiling daikon.
** See Fundamentals 101 for more on kakushi bocho scoring technique.

Recipe by Kikkoman Corporation

1 C (U.S. cup) = approx. 240 ml; 1 T = 15 ml; 1 t = 5 ml