At the counter of a restaurant called Tokyo Kaikan in Los Angeles’s Little Tokyo, in the late 1960s, a master was wrestling with a practical problem. Chef Ichiro Mashita could not get fatty tuna belly, toro, in every season. His solution was bold: he answered toro’s silken richness with California’s own fruit, the avocado. Crab, avocado, cucumber; the skeleton of the California Roll was set.

The second invention came from the customers. Americans disliked the black sheet of seaweed and would pick the roll up and peel the nori off. The counter answered by turning the rice outward; thus was born uramaki 裏巻き, the inside-out roll. Ura means the hidden side; the nori went into hiding, and the matter was settled.

The story has a northern front as well. Hidekazu Tojo, a chef who emigrated from Osaka to Vancouver, says the invention was his, and in 2016 Japan named him a goodwill ambassador of Japanese cuisine. The case of Los Angeles versus Vancouver is a friendly one, and will likely never be decided.

Whoever invented it, the verdict is in: for millions of people, this roll was the first sushi of their lives. The bite that opened the door keeps its seat of honor at our counter.