Junichiro Koizumi, the Japanese prime minister, is a political enigma, but there is no doubting either his charisma or his determination to reform the country's hidebound domestic economy. His supporters, including the Japanese voters who handed his Liberal Democratic party a two-thirds majority in the September general election, are therefore anxious about his plans to step down on schedule next year.

Mr Koizumi's reluctance to stay in office for more than five years - he says he wants to listen to music and dine out - contrasts admirably with the tendency of his peers in other countries to overstay their welcome. Even so, his planned departure raises the question of who will take charge of his political legacy, particularly the privatisation of the giant postal savings bank, and manage Japan's imminent emergence from deflation and stagnation.