Photo As China’s economy has cooled, Japanese businesses like Tsutomu Nyuwa’s metalworking shop have experienced a slump in sales. Credit Kentaro Takahashi for The New York Times TOKYO — In its small way, Tsutomu Nyuwa’s metalworking shop in Yasugi, Japan, has been feeding the economic boom 700 miles away in China. Many of the precisely machine-tooled gears, bearings and other components turned out by Mr. Nyuwa and his 14 employees end up on Chinese work sites, in the engines of the giant earthmovers that have powered China’s breakneck pace of construction. But with Chinese growth now slowing, Mr. Nyuwa’s business is slumping — along with the rest of the Japanese economy, which data released on Monday showed is in recession again. Japanese equipment makers like Komatsu, Kubota and Hitachi Construction Machinery are selling fewer excavators and bulldozers in China and, in turn, are buying fewer parts from manufacturers like […]