Kan, a 63-year-old veteran lawmaker, founded the Democratic Party with Hatoyama more than a decade ago and shot to fame as health minister in the 1990s, when he spearheaded a campaign to unveil health ministry's scandal over HIV-tainted blood products.

Naoto Kan, Japan's Finance Minister addresses a press conference in Tokyo, capital of Japan, on June 3, 2010. Japan's DPJ chooses Naoto Kan as new Party President on June 4. [Xinhua]

The new DPJ chief, who served dual roles of deputy prime minister and finance minister, is widely regarded by his peers as a no-nonsense politician.

Kan has said that his "ordinary" background as opposed to a number of his predecessors' privileged upbringings and connections that catapulted them into positions of political power, will serve him well as he tries to convince the public that the cabinet he forms will be the one "they hope for."

"I will make the Democratic Party a clean party that can be trusted by the Japanese people," Kan said at a recent news conference alluding to Hatoyama and ruling party heavyweight Ichiro Ozawa both resigning partly due to funding scandals.

"This has caused mistrust among the public. Ozawa should be quiet for a while. That would be good for him, for the Democratic Party and for Japanese politics."

Kan believes the outgoing administration erred on economic and fiscal policies and he will, as prime minister, quickly go about compiling new growth strategies and fiscal reform plans.

"I plan to achieve a strong economy, public finances and social welfare system in a unified manner."

"For the past 20 years, Japan's economic policies were wrong. I want to seek to boost growth by creating jobs," Kan said.

He began his political career as a civic activist in the 1970s and ran for office three times before winning a lower house seat in 1980 for the now-defunct Socialist Democratic Federation.

With his ordinary upbringing, Kan would represent a break with the past several prime ministers, including Hatoyama, whose fathers or grandfathers were also prime ministers.

The son of a businessman, Kan was born in Yamaguchi prefecture in southwest Japan and graduated from the Tokyo Institute of Technology's science department.

Once he selects his new cabinet to represent the party he will likely attend an attestation ceremony at the Imperial Palace, at which Emperor Akihito will inaugurate him as Japan's 61st prime minister.

Hatoyama and his entire Cabinet stepped down together in the morning, prior to the Diet's vote on the country's new leader in the afternoon.

Hatoyama stepped down abruptly Wednesday due to mishandling of the Futenma U.S. base relocation and fund issues. He was the fourth prime minister to resign in four years, only eight months after he swept into power in a historic general election last September.