

A search on restaurant review site Tabelog reveals 15 hits in the entire country, all in reviews where people claim to have eaten this. You can peel the shell off from the broadest part of the tail with. Suck the yellow stuff out of the crawfish head, also known as crawfish butter. Turn the head to separate it from the tail. The index finger and thumb should be on either side of the shell. The gelatinous eyeballs, which are fatty-tasting, slippery little suckers. Place both hands on the tail joints of the crawfish. You could use the whole fish, or a meaty fillet, but then you couldn't enjoy the diversity of textures and tastes to be gotten in one head. This is not an everyday item by any means and it falls squarely into the category of chinmi ("rare tastes"), meaning odd foods/acquired tastes meant primarily as accompaniment for drinks, and the kind of thing that makes an occasional appearance in the daily specials, not a fixture of the regular menu. Yet fish head soup just wouldn't be the same, or even close to it, without a good fish head. Incidentally, the pupils and eye sockets stay hard, you only eat the stuff in the middle. Like the name says, this consist of tuna eyeballs (which are pretty big!) stewed for hours on end in the usual Japanese soy-mirin-sake-dashi base until they more or less completely fall apart into mush, as shown in this picture (not CC so I can't copy it in, alas). It's occasionally branded as the more palatable "マグロのDHA煮" after DHA, a fatty acid found in eyeballs and fish oil that's supposedly good for you. I'm aware of only one fish eye dish in Japan, namely maguro no medama-ni (マグロの目玉煮), "stewed tuna eyeballs".
