Tofu is pressed until the water has gone out of it. Egg and sugar are worked in, and the mixture is baked in the shape of a castella sponge. It is a confection, and about half of it is bean curd.

It belongs to the southern part of Akita — around Daisen and Yokote, where the enthusiasm for it is noticeably stronger than anywhere else in the prefecture. It appears in the little dishes served at weddings and funerals, and it is also an afternoon snack and something to put beside tea. The same object turns up at a memorial service and at a celebration, which is unusual for a sweet.

The reason it exists is documented plainly. Sugar and eggs were expensive for ordinary households, and castella needed both. Tofu was itself something eaten on special days, and it was the ingredient that could be had. So a luxury cake was built by substituting one luxury for another rather than by economising.

Eating it, the texture is dense and moist and slightly grainy. It does not have the lightness of an egg sponge; what stays is the weight of the bean curd underneath. It was made for new year, for rice planting, for the days that were marked — and not otherwise.