Rice is definitely the most important crop in Japan. Then, Japanese prefer short grained Japonica rice which is eaten daily, sometimes three times a day as boiled rice using rice cooker. Also rice is the main ingredient for sake. Rice can be bought at supermarkets and also at rice stores. Rice are sold in 1 kg, 2 kg, 5 kg and 10 kg usually.
Japanese ate 118.3 kg per person/year in 1962 but the consumption is reducing each year, reaching 70 kg per person/year in 1990 and 53.5 kg per person/year in 2018. Way of living has been changed and people are eating outside or take away meals from stores more than before.
On the other hand, quality of rice has been improved. Japanese buy only domestic rice and prefer to eat high brand rice; such as Koshihikari. Koshihikari is probably the most famous and popular high brand rice in Japan, especially the one harvested in Uonuma region in Niigata prefecture. Other famous brands/cultivars are Hitomebore, Akita Komachi and etc.
Each brand has its distinguish taste, therefore if you can taste the difference of the rice, you are becoming more to Japanese.