Mrs Akie Abe is known to hold hands with her husband in public, post photos of their daily lives on social media and even speak out publicly against some of his policies.
In other words, she is not the typical faceless wife of a Japanese Prime Minister but has been such a vocal critic of Mr Shinzo Abe that she is dubbed kateinai yato, or "at-home opposition".
While she has made waves for campaigning for liberal causes such as lesbian, gay, bisexual and transgender rights - which has softened her husband's hawkish image - she is now the subject of a controversy over her links to an ultra-nationalist school, a scandal that has affected Mr Abe's approval ratings.
Born in Tokyo in 1962, Ms Akie Matsuzaki was born into privilege, daughter of the former president of Morinaga & Co, one of Japan's largest confectionaries.
She attended Sacred Heart School in Tokyo from kindergarten, before studying at the Sacred Heart Professional Training College.
She was introduced to her husband-to-be by her former boss at advertising giant Dentsu.
"We went out for dinner and I found (Shinzo) to be really funny," she told The Japan Times last year.
"He is eight years older than me. He comes across as being mature and is knowledgeable about a wide variety of things so I both respect and admire him."
Mrs Abe, once a disc jockey nicknamed Akky, had already made an impression during her husband's first short-lived term in office from 2006 to 2007, for her relative youth and outgoing public persona.
She did not shy away from holding Mr Abe's hands in public and even spoke publicly of her inability to bear children.
After her husband's first tenure as Prime Minister, she pursued a master's degree in social design studies at Tokyo's Rikkyo University and opened an organic restaurant, Uzu, in central Tokyo.
It was during her husband's return to power that she fully embraced her role as First Lady. She told The Japan Times: "I'm one of the few people in this country who can talk to a wide range of people, from the Emperor to the homeless."
On her Facebook page, where she has more than 130,000 followers, she posts daily about the events she attends, the people she meets and, sometimes, goofy pictures of her husband grinning or eating ice cream.
In an interview with Bloomberg last year, she said: "I want to pick up and pass on the views that don't get through to my husband or his circle. As his wife, there are times when I don't want to attack him too much. Other times, I really feel I have to tell him something."
She has gone so far as to openly question the policies of Mr Abe's ruling coalition, for example, on the use of nuclear power.
Mrs Abe is also known for taking the lead over certain issues. She took the initiative to pay respects to the war dead at Pearl Harbour in a quiet visit last August - four months before Mr Abe, and when Tokyo was dithering over whether it should reciprocate then US president Barack Obama's visit to Hiroshima.
She attended a rally in Okinawa opposing the construction of helipads for the US military, without a posse of bodyguards.
She has also been vocal about the urgent need for workplace reforms, saying: "Society can't continue in this vertical, confrontational pyramid structure that's made by men. What can change is women's tolerance, flexibility and motherliness."
However, she has now come under intense public scrutiny for her links to ultranationalist education group Moritomo Gakuen, which is known for making its pupils bow to portraits of the Emperor and recite a pre-war militaristic edict daily.
The group was found to have benefited from a sweetheart real estate deal - the plot of land for its new Osaka elementary school was sold only at one-seventh of the appraised value.
The school's launch, which was slated for next month, is now scuttled after the Osaka government revoked its licence.
The operator's chief Yasunori Kagoike, testifying under oath in the Diet last week, singled out Mrs Abe, who was honorary principal of the upcoming elementary school until last month, for her alleged role in negotiating for an extension to the lease of the land, although this was eventually not granted.
He also claimed that she had helped Mr Abe make a secret one million yen (S$12,600) donation to the school.
Mrs Abe has denied the claims but the scandal has raised many doubts over the role of this most unusual Japan First Lady.