With high approval ratings stoking speculation that Shinzo Abe could become Japan's longest-serving prime minister in recent history, he faces the risk of becoming complacent. Enter Akie Abe, his wife of 29 years.

The 54-year-old daughter of a confectionery magnate is known as "the household opposition" for speaking out against key Abe policies such as backing the Trans-Pacific Partnership trade pact, exporting nuclear technology and expanding a U.S. military base on Okinawa.

"I want to pick up and pass on the views that don't get through to my husband or his circle," Akie said in an interview last week at a restaurant she opened in central Tokyo four years ago. "That is a bit like an opposition party, I suppose."