In late May, a nurse in Miyagi Prefecture sent a letter to Kahoku Shimpo, complaining that she had to give up on helping administer coronavirus vaccines — despite a shortage of qualified medical workers — due to what is called the "¥1.3 million income hurdle."

Under the current system, if a spouse earns less than ¥1.3 million a year, they can be exempt from pension premium payments and be covered by the main earner's corporate pension plan. This means that spouses who earn ¥1.3 million or more need to pay for premiums for pension and health care.

The Miyagi nurse currently works as a part-timer below the ¥1.3 million income threshold as her husband's dependent. And she is one of many part-time medical workers who has been unable to assist with the vaccine rollout because of the income cap.