Naoto Kan, the straight-talking populist named Japan's new prime minister, faces a host of daunting tasks, from reviving the nation's economy to cutting back its national debt. But first he must survive an urgent test: Win back voters disgusted by the broken promises of his predecessor, Yukio Hatoyama, by next month's upper house elections. "Kan brings passion to the post. He is known as 'Ira-Ira Kan,' the 'Irritable Kan' because he's got a temper. The guy cares about politics," said Jeff Kingston of Temple University, Japan Campus (TUJ). "I think that the voters will respond to him."