Add the ground meat to a small frying pan (no oil needed) and cook over medium heat until the color changes from pink to brown.

Once the meat is browned, add the soy sauce, sake, and mirin. Continue cooking, stirring, until the mixture is crumbly and most of the liquid has evaporated.

Drain the pickled red ginger and roughly chop it. Place it in a bowl. Add the cooked ground meat and mix well, then add the cooked rice and mix everything together.

Shape the mixture into rice balls in your preferred shape. Sprinkle with toasted sesame seeds and wrap with nori cut to your desired size. Enjoy!