That's incorrect. Kokuho rice is based on Pearl Rice. Pearl Rice is a breed from the Yangtze Delta River Region. People there eat this breed, such as Shanghai, Nanjing, Zhejiang, Jiangsu, Anhui. The Japanese stole seeds from that area during the invasion of China from the first and second Sino-Japanese wars and made their Japonica breed.

The long grain Jasmine rice is popular with southern China and Southeast Asia because it's from Southern China.