Hoya, the sea squirt, is said to carry all five tastes at once: sweet, sour, salt, umami, bitter. Whether or not that is literally true, it is the reason people who like the stuff find it impossible to describe to people who do not.

Along the Sanriku coast it is eaten from around May through August, when it is landed, and again in December and January when the animals are spawning, which some people prefer.

There is farmed hoya and there is wild hoya, and the difference between them comes down to depth. Wild ones sit on the seabed at twenty to thirty meters, which is beyond casual diving. In Hirono, at the northern end of the Sanriku coast, there is a diving tradition called Nanbu-moguri, born more than a hundred years ago, and it is those divers who bring up wild hoya, one at a time, by hand.

The preparation is close to nothing at all. Shell and innards removed, cut into manageable pieces, dressed with cucumber, salt, and a simple two-part vinegar. That restraint is deliberate. With five tastes already in the animal, the only job left is to get out of the way, and in the vinegar they come forward one after another rather than together.