Considering how past Prime Ministers of Japan have resigned over less this really isn’t too surprising:

Japanese Finance Minister Naoto Kan, center is the likely next Prime Minister of Japan.

Embattled Japanese Prime Minister Yukio Hatoyama resigned Wednesday to improve his party’s chances in an election next month, after his popularity plunged over his broken campaign promise to move a U.S. Marine base.

Finance Minister Naoto Kan, who has a clean and defiant image, emerged as a likely successor. He signaled he intends to run for leadership of the ruling Democratic Party of Japan at a party meeting to be held Friday.

Sweeping into office just eight months ago by defeating the long-ruling conservatives, Hatoyama captured the imagination of many Japanese voters with his promises to bring change and transparency to government, as the country grappled with economic stagnation and an aging, shrinking population.

So when he failed to deliver on his pledge to move the Marine Air Station Futenma off the southern island of Okinawa and his staff got ensnared in a political funding scandal, his approval ratings rapidly sank, falling below 20 percent.

“He could not live up to the huge expectations,” said Tetsuro Kato, professor of politics at Hitotsubashi University in Tokyo. “He just proved himself to be a rich kid without experience and leadership skills.

“The expectations were so great, the disappointment was also great,” he added.  [Associated Press]

By resigning Hatoyama has finally done something to differentiate himself from former Korean President Roh Moo-hyun who decided to stick around for 5 years as a lame duck President.  Heck if in the US Presidents had to resign for making false campaign promises I wonder how long they would last?