Inside the body is a mass of eggs that look like grains of cooked rice. That is where the name comes from: ii, rice, dako, octopus. The eggs run five or six millimeters across and there are said to be between two and five hundred in a single animal.

They reach about thirty centimeters overall and are taken in bottom trawls and in octopus pots. In Okayama the fishing is around Shimotsui, off the Kojima district of Kurashiki, on the Inland Sea, which is one of the two coasts the species is chiefly associated with.

The sources disagree about when the eggs are there. One says the ones eaten simmered in Okayama are winter animals, carrying eggs in the mantle in the cold months. Another gives spring as the season and spring as the spawning. I have not been able to reconcile them, so both are here.

The cooking is simple enough to describe in one breath. Rub the octopus with salt and wash it to get the slime and grit off, parboil it in water, then put it in soy sauce, mirin, sugar, and water with a drop-lid on top and simmer for around twenty minutes. It is done whole, so the head arrives intact and you bite into it, and what is inside comes apart in the mouth exactly like rice. The name is a description.