The tea served at a sushi counter in Japan has a name of its own: agari 上がり. In counter slang the word means the one that comes at the end; but in truth the tea is there from beginning to end. Hot, strong green tea cleans the palate between two bites, so the fat of one fish never blurs the delicacy of the next. This is why masters keep it deliberately dark and choose wide cups over small ones. Here, tea is not a beverage; it is a working member of the counter.

The leaf itself came to Japan with monks; from the eighth century onward, clergy traveling to China carried back seeds and the habit. The islands took to tea so completely that it became the measure of daily life: sencha 煎茶, the steam-freshened leaf of the fields; hōjicha, its roasted sibling; genmaicha, blended with toasted rice. All are moods of one plant, Camellia sinensis, and the secret of their greenness is speed: the leaf is steamed right after harvest, stopped before it can oxidize.

So the plain cup beside your plate is not decoration. Sushi and tea have shared the same counter for four hundred years; one speaks, the other clears the space between sentences.