The public's top pick to become the next prime minister says the country is not ready for the scale of change he thinks it needs.

Shinjiro Koizumi, the 38-year-old son of popular former Prime Minister Junichiro Koizumi, consistently leads polls asking who should succeed long-serving Prime Minister Shinzo Abe. As the most prominent member of the ruling Liberal Democratic Party's new guard, he wants quick reforms to manage the country's rapidly aging population.

"If you look at Japan now, people don't want to change much," Koizumi said in an interview at his office in Tokyo on Wednesday.