Where the world's biggest pension fund goes, half a trillion dollars is set to follow.

Three retirement managers for Japanese civil servants and private school teachers with ¥30.4 trillion ($296 billion) will mimic the asset allocation changes being planned by the ¥126.6 trillion Government Pension Investment Fund, according to Takatoshi Ito, an adviser to lawmakers on the overhaul.

Smaller funds with the equivalent of $205 billion are also poised to follow. Public pension managers must use the same investment guidelines by October 2015, according to information on the health ministry's website.