Go is the word for soybeans soaked, ground, and boiled, the stage before anything is strained or set. The dish is named after that intermediate state, which tells you something about how closely people here were watching the process.

Ordinary tofu is set with nigari. This is not. Soy milk is thickened with kudzu starch or another starch and allowed to firm up, so what you get is soft but pushes back against the spoon, closer to a set custard than to a curd. The surface has a wet shine on it.

It belongs to Arita in Saga. The story told locally is that in the early Showa years a tofu maker from Arita went to Nagasaki to buy soybeans, got talking with a Chinese resident there about a starch-set tofu, and brought the method home. Another version credits the grandmother at a sushi shop in the same town, who is said to have learned it in 1929 and put it on her menu.

Normally it comes with sesame and soy sauce poured over, as a side dish partway through a meal. Pour black syrup and roasted soy flour over the identical block instead and it becomes dessert. One preparation that works at both ends of the table, without altering anything but what you put on top.