The Democratic Party of Japan (DPJ), landslide winner of that country's general election a week ago Sunday, has formed an ideologically diverse coalition government.
The Japanese situation seems to be similar to that in India, when the Indian National Congress, also known as the Congress Party, began to lose its iron hold on power during the 1970s. Anti-Congress coalitions were formed, with little to hold them together, other than opposition to Congress and its leaders, most of whom have been descendants of independent India's first prime minister, Jawaharlal Nehru. With so little common ground, those coalitions were unstable, and only temporarily kept Congress out of power.
The Japanese Liberal Democratic Party (LDP) has, up to now, played a dominant role in its country's politics, similar to that of the Indian National Congress. The new coalition in Japan, which spans the ideological spectrum, seems to be based on opposition to the LDP, more than anything else.
The New York Times report to which I've linked above, describes policy disagreements that have already affected the coalition relationships. It will be interesting to see how stable that coalition proves to be, over time.
The whole reason for forming a coalition is that, while the DPJ now has a hefty majority in the parliament's lower house, the House of Representatives, it lacks a majority in the upper house, the House of Councillors. If the DPJ can continue to gain upper-house seats in subsequent elections, it may not need to worry about a coalition, at all.
Elections to the House of Councillors are somewhat similar to those for the United States Senate. Terms are six years, and there is an election every three years for half of the seats. Therefore, a change in party strength is likely to happen more gradually than in the lower house.
The DPJ's situation in that respect is similar to that of the Democratic Party in the U.S., which won a substantial majority in the House, when voter sentiment turned in its favor in 2006, but only a razor-thin majority in the Senate. Then, the Democrats were able to expand their Senate majority, when more seats came up for election in 2008.