There is no whale in it. The name says whale and the ingredients are glutinous and non-glutinous rice flour kneaded with water, walnut pieces, and sugar syrup, steamed in a seiro.

Several explanations for the name are offered, and none has won. One says it was written with characters meaning keeps well for a long time, and the reading drifted. One says it looks like shiokujira, salted whale blubber with the skin still on. One says a single bar used to be made from one sho of rice, and the name is about the size of the thing.

The likeliest account of the origin is more specific. It was made as field rations in the time of Tozawa Masatsune, the third lord of the Shinjo domain, roughly three hundred years ago, and Shinjo is taken to be where it began.

What it became is a festival sweet. It is set out with the hina confections at the peach festival by the old calendar, in early April here rather than March. It is made in white sugar, brown sugar, soy sauce, miso, and with bean paste inside, and from milling the flour to lifting it out of the steamer takes about two days. Everything about it is documented except the one thing people ask first.