Oryza sativa – what we know as the rice plant – can be divided into two major subspecies, japonica and indica. The latter, used widely in cooking across southern Asia and parts of China, is characterised by long, flat grains which fluff up when cooked. By contrast japonica rice, cultivated predominantly in Japan and Korea, has a much shorter, rounder grain and a glutinous texture which makes it perfect for picking up with chopsticks and moulding into sushi.

In Japan japonica rice is further categorised as uruchimai (ordinary rice) and mochigome (glutinous rice). Uruchimai is recognisable for its short to medium translucent grains and has a number of uses including sushi and sake, while the short, round, opaque grains of mochigome are usually used in desserts or soaked and ground into a paste to make mochi, the chewy rice cakes famed for causing on average one hundred choking injuries a year in Tokyo alone.

Rice is intensively cultivated in Japan despite the relatively small area of agricultural land, and imports are strictly regulated and subject to steep levies by the Japanese government to protect the domestic rice industry. The cost of domestically grown rice is also, on average, relatively high but this premium is widely accepted both as a reflection of its quality (compared to imported rice) and due to the importance of rice in Japanese culture as a whole. Although consumption has fallen by around 20% in as many years, rice still forms a staple part of the Japanese diet and the country is among the top ten rice producers in the world. The Niigata Prefecture, known by many as the rice capital of Japan, is famed for the quality of its output, particularly Uonuma which produces high quality Koshihikari rice.