Finance Minister Yoshihiko Noda has been chosen to become Japan's sixth prime minister in five years.
The 54-year-old must deal with a resurgent yen that threatens exports and forge a new energy policy while ending the worst nuclear crisis since Chernobyl.
He must find funds to rebuild from the 11 March tsunami at a time when huge public debt has already triggered a credit downgrade.
Doubts run deep as to whether Mr Noda will have sufficient support and stay in office long enough to tackle the long list of economic woes and cope with a nuclear crisis.
'Noda has inherited all the same problems - a divided parliament, a divided party, a strong yen, a Tohoku (northeastern Japan) desperate for progress on reconstruction and an early end to the nuclear crisis,' said Jeffrey Kingston, director of Asian Studies at Temple University's Japan campus.
'I think the honeymoon will be very short-lived.'
No Japanese prime minister has lasted much more than a year since 2006 and most market players polled by Reuters this month thought the next government head would be no exception.
Mr Noda, who will be confirmed by parliament tomorrow, will be the third premier since his ruling Democratic Party of Japan swept to power in 2009, promising change.
