At that time, it was identified as the core of the nation's industrial complex. Other than the Miyagi area, nearly all manufacturing industry in the nation lies in this zone, accounting for 81% of the nation's economic output in 2007 (about 4–5 trillion).
In 2007, it was determined to be the central hub of Japan's industrial system. The majority of the country's manufacturing sector, excluding the Miyagi area, is located within this zone, generating 81% of the nation's economic output (around 4–5 trillion dollars).