Apart from this, frozen vegetables are also convenient in the kitchen. Frozen vegetables only need to be warmed up or stir-fried and they are ready to be eaten. People in the industry have expressed worries that this will become a larger threat to the Japanese vegetable industry.
Data on trade from the Japanese Ministry of Finance shows that the import volume of frozen vegetables has grown steadily since the 1990's. The import volume of frozen vegetables in 2017 was the largest volume in Japanese history. The majority of that import volume is produced by China and The United States. The imported vegetables are mainly mixed vegetables used by restaurants for stir-fried dishes, and vegetables that need to be cooked.
The import volume of frozen vegetables in Japan in 2017 was 1,009,000 tons. That is an increase of 7% compared to the previous year. This increase was most notable for stem vegetables. Analysts of the Japanese Frozen Food Association state that "It's not only businesses that are influenced by rising prices of domestic vegetables, but households also increase consumer demand for frozen vegetables."
Source: people.com.cn