【Reading】いっかん

【English Name】Ikkan

"Ikkan" is the unit used when counting pieces of nigiri sushi. Most sushi restaurants today use ikkan to mean a single piece of nigiri, but the view that ikkan equals two pieces remains deeply rooted, and it is one of those topics on which opinion has long stayed divided.

Among the several hypotheses proposed about its origin, the view that it derives from the Edo-period currency and weight unit "kan" is the most widely accepted. A tradition associating the weight of a single Edo-period nigiri with one kan (about 3.75 kg) of hole-pierced coins survives, but there is little direct documentary evidence to support it.

Edo-period nigiri sushi was far larger than today's, and a single piece is thought to have been a full serving. As sizes shrank in the Meiji era, the style of dividing one serving into two and serving them became mainstream, and the "ikkan = two pieces" way of counting is thought to have arisen from this.

Entering the 2000s, industry bodies such as the National Federation of Sushi Trade Sanitation Business Cooperatives put forward "ikkan = one piece" as the standard usage. Most conveyor-belt sushi chains and restaurants adopted this interpretation, and many shops express quantities as "one piece" or "two pieces" to prevent confusion in orders.