By Chris Hogg
BBC News, Tokyo
Shinzo Abe was the "princeling", a man with good looks and an impeccable political pedigree - chosen to lead his party last autumn, many said, because he was the candidate most likely to win elections.
Shinzo Abe's star has plummeted in the last 10 months
He became Japan's first prime minister born after the war.
He got off to a flying start, literally - travelling to Beijing and Seoul within days of taking office to try to rebuild the country's troubled ties with its near neighbours.
His Cabinet's approval rating was above 60%.
But that was then.
This week, his Cabinet's rating sank to just 28%.
Members of his own party, the Liberal Democratic Party (LDP), are warning that it could lose control of the country's upper house in the election due later this month.
There are 121 seats of the 242 seats in the upper house up for election.
The LDP and coalition partners New Komeito hold 58 seats between them, which are not contested this time round.
So the ruling camp needs to win 64 of the 121 seats to hold on to the upper house.
A series of blows
There are real doubts that it can achieve this. Mr Abe's administration has been beset by problems in recent months.
He has lost his reform minister and his head of tax policy, who both resigned after financial scandals.
His farm minister hanged himself after he was linked to party funding scandals and bid rigging.
His health minister embarrassed him by describing women as "breeding machines".
And his defence minister resigned after controversial remarks about the US atomic bombings of Japan.
But perhaps most damaging of all, it has emerged that, over the years, Japan's government has lost the 50 million records of pension contributions ordinary people have made.
These errors were made before Mr Abe took office, but it is a scandal that has erupted on his watch.
"Prime Minister Abe has badly mishandled many of these issues," argues Professor Koichi Nakano from Sophia University in Tokyo.
"In an attempt to imitate [his predecessor Junichiro] Koizumi's image as a strong leader, he keeps on saying he bears ultimate responsibility for them."
Mr Nakano believes this is a serious tactical error, "when one is both ill-informed and has poor judgement".
Is that fair? Or was it simply too hard to follow an act like that of the hugely popular Junichiro Koizumi?
Fumio Kyuma is one of several ministers who ran into trouble
Dr David Satterwhite, a specialist in North East Asian political affairs and executive director of the Fulbright Commission in Japan, argues that Mr Abe's early popularity indicates that following closely on the heels of Mr Koizumi was not the problem at all.
Instead, he agrees with Mr Nakano that his very low level of popularity now is due to a combination of specific mistakes on policy and the "explosion" of the pensions scandal.
"In policy terms [his adoption of] an overtly nationalist agenda - revision of the constitution and educational reforms to inculcate patriotism - over a more distinctly livelihood-orientated, economic agenda that would reassure the public of his commitment to the reformist initiatives of his predecessor, was a strategic gamble."
His Cabinet's low approval ratings, and - just as significant - an increase in the number of people who tell pollsters they actively disapprove of what the administration is doing, is perhaps evidence that the gamble has not paid off.
Takao Toshikawa, the editor of Insideline, a political newsletter, believes the prime minister has been badly advised.
"Mr Abe's inner circle, including the Chief Cabinet Secretary Yasuhisa Shiozaki, and Hiroshige Seko, senior adviser, public relations, do not have the experience to stand up to the LDP's traditional power brokers," he says.
As a result, he points out, Mr Abe has been forced to make the big political decisions himself, and yet he, too, is relatively inexperienced - the first ever lawmaker to become prime minister after being elected to parliament just five times.
So is he on the way out? Are we about to return to the tradition of Japanese prime ministers lasting just months? Will he be forced to step down if he loses the upper house elections?
Election litmus test
Prof Jun Iio, from the National Graduate Institute for Policy Studies, believes there is a strong possibility that the opposition Democratic Party of Japan (DPJ) will win the election.
Constitutionally that would not mean the prime minister has to step down. It is the lower house that decides who leads the country.
But in the past, LDP leaders who have lost control of the upper house have fallen on their swords.
"Some politicians have made clear that Mr Abe should resign if his party gets less than 44 [of the 121 contested seats]," Mr Iio says.
"But in my opinion it is plausible that he will remain in place even if he is defeated in the election because the LDP has few other candidates to be prime minister."
Mr Abe's pursuit of a nationalist agenda has alarmed some
Mr Nakano is more pessimistic. A sound defeat "would mark the end of his premiership," he says.
And losing control of the upper house would not just make life difficult for the prime minister himself, Mr Satterwhite points out.
"It could jeopardise the ability of parliament to effectively pass much-needed legislation, which would be a direct blow to market confidence in his premiership," he says.
Put simply, it could lead to a legislative log-jam and that would be bad for the LDP as a whole as it would not be able to push through its political agenda.
There is one hope for Mr Abe and his embattled Cabinet.
The DPJ has demonstrated in the past a consistent ability to rip the silver linings off clouds and squander any opportunities they are given.
And, as Mr Iio points out, with few strong contenders to replace him, if Mr Abe can minimise the losses, or perhaps persuade independents or small parties to back him in the event of a close result, he may yet survive a little longer.