It's a rite of spring: Major corporations hire fresh university graduates en masse every April, starting them all at the same salary with assurances of rising pay and lifetime employment.

But lately, some companies, including Rakuten, SoftBank and Line Corp., are breaking with that tradition, signing up new employees with coveted technical skills months earlier — and paying them more than other new recruits.

As competition for workers grows in Japan's shrinking labor pool, traditional seniority and group dynamics are giving ground to the more individualized, merit-based employment system found in the West.