Gyudon (strips of beef on a bowl of rice) have become a cornerstone of my diet, but there could be an end to it: Yoshinoya, the biggest chain of gyudon restaurants, imported all of its beef from the United States, which have been slapped with an import ban because of the mad cow disease at the beginning of this year. Today or tomorrow, Yoshinoya will run out of stock. They already changed their menu to include salmon, roe, pork and chicken (in another unlucky turn of events, shortly after the introduction of chicken meat, the bird flu struck, sending Yoshinoya even deeper into trouble), and from Thursday gyudon will no longer be available in Yoshinoya's 986 outlets (except for its original shop in Tsukiji which for historical purposes continues to sell Japanese beef, just like it did back in 1899). It is not without irony that the 80 shops Yoshinoya West operates in the United States will still be serving the same American beef that is now banned in Japan.

I cannot help but wonder if Yoshinoya's announcement to stop making gyudon is not just a marketing stunt. They say they cannot use Australian beef because it is not suited for gyudon. That has not stopped Matsuya, the number two chain. At the moment, Yoshinoya is enjoying great sales as everyone is rushing to place their last orders. Official numbers put sales 20% above usual levels, and the shop was crowded when I went there for lunch today.

So maybe there is hope.