As Japan seeks to rebuild disaster-hit regions and gears up to build new facilities for the 2020 Summer Olympics, its construction industry finds itself short of new workers mainly as a result of shrinking construction investment since 2000.

Young people's reluctance to accept physically tough labor for low wages is another factor holding back the emergence of a new generation of site workers.

"Many of the young people who joined (construction companies) in the spring will quit in their first year after not being able to withstand the summer heat or the winter cold," an industry official said.