Kate means to bulk something out. There was not enough rice, so cooked vegetables were mixed through what there was, and the bowl came out full.

Chichibu is poor country for growing rice. Even where it could be grown, the crop went to the landlord as rent or was sold for cash, and once a household had set aside what it needed for weddings and funerals there was very little left in the house. Something had to make the remainder go further.

Dried taro stems, dried shiitake, carrot, burdock, fried tofu, sometimes daikon or potato — whatever the house had that would take seasoning and hold it. They are simmered with seasoning first and then stirred through the rice, and the grain stops being the point of the dish somewhere in the process.

Here is the part worth noticing. The seasoning includes soy sauce, and soy sauce, on a farm, was not an everyday purchase — it came out for occasions. So a rice dish invented to disguise a shortage acquired a festival ingredient, and ended up being served when people gathered. It went onto the table alongside sushi, at the same sort of gathering, for the same sort of reason. Something made out of not having enough became the thing you put in front of guests.