Why are there so many opposition parties (at least seven) in Japanese politics?

Simple -- egos.

Because Japan no longer has a direction.

Because they think people care about the stupid little differences in policy thought up by crooked old men.

How is 7 many? In Europe it's fairly standard to have dozens. It's only 2 in the States because any more than that would be too confusing for Yanks

Law of the playground. Anyway, same number or more in many other countries. Us is one of few where there are only 2 real parties.

I like to have more than 2 choices in an electoral system where your vote against the larger parties isn't a useless one.

@Jimizo

I like to have more than 2 choices in an electoral system where your vote against the larger parties isn't a useless one.

Problem is, mate, that a vote for the Tories or Milliband's mob is equally useless anyway....

Any country that doesn't have runoff voting is probably headed for a two-party system. George W. will be your next leader.

any vote that only relies on 2 choices for the future of a country is destined to fail.

There's not only two parties in America. Take a look at an election ballot.

Because Japan claims to be a democracy and in a democracy, political parties abound. The voice of the people and all that. Also, as Sensei258 pointed out, there are more than two political parties in the US. Some, like Inoki's Peace and Sports party, are small.

I see my original post has gotten 5 thimbs down, but no one has refuted it. The plain fact is that politicians who would be small players in the LDP often take the road of forming their own party, because they hope to become more of a player in Diet affairs, should the LDP not be able to command an actual majority. And the fact also is that the actual policy differences between all these parties is very small. Sorry, but anyone who doesn't believe that Ozawa, Ishihara, and Hashimoto, to name just three, are not driven by pure ego is simply not facing reality.

I really don't know... We'll have to ask the Japanese...

I don't think heavyweight Japanese politicians really feel they need to belong to any particular party in order to win elections, having very well-established local support bases that either they've built up themselves over however many decades they've been alive or their Diet member fathers and grandfathers have built up for them. For instance I recall one senior LDP member (Shizuka Kamei, maybe) quitting the party over the postal privatisation issue but still getting re-elected. I suspect, though, that this makes them feel more obliged to do what their constituents want than to tow the line in a big political party. And if they have a bit of cash to spare like Ichiro Ozawa who could apparently bankroll half of the DPJ by himself, they can break away and take a few like-minded acolytes with them.

Is 7 a lot? i think most European democracies have at least that many parties......

This is mainly a result of NHK's policy of giving equal airtime to all political parties. So any group of two or three elected politicians usually decides to form a party because NHK will have to give them equal airtime in the Sunday morning program and during election campaigns. Of course in the end the LDP benefts because all the numerous opposition parties seem like colorless no-hopers.

any vote that only relies on 2 choices for the future of a country is destined to fail.

The number of major political parties in Japan vs America is actually irrelevant. Both countries have succeeded in amassing huge debts and calcified government bureaucracies despite their different governing structures and party systems.

Anyone that actually has any understanding of American politics understands that the two major parties contain within them all of the same sorts of factions found in countries with a parliamentary governing structure. Coalitions are created within the parties. Sometimes this large coalitions between the Left and Right fracture and cause the same kind of paralysis found in closely divided parliamentary coalitions.

because Shintaro Ishihara keeps starting new parties?

I wouldn't have minded if some of the smaller parties would have won seats to balance the LDP and much of the pork barrel spending to inefficient sectors (construction, agriculture, et. al.) that has come with it.