All the major parties in Japan's parliamentary system have long been hesitant to ever reprimand or demand expulsion of a sitting Representative. It basically takes a conviction for a crime *and* the full course of appeal, and only when the malefactor is actually on their way to prison do they seek to remove them from office. That is, of course, just... in the case of prosecutable criminal offense... but where the system often fails is when impeachment is deserved for reasons not precisely indictable as criminal. Flaunting the rules of party and chamber, for example.
Well, maybe this time will be different? We are speaking of the all-too-convincing accusations against Ozawa Ichirou (I. Ozawa). He wouldn't be removed from his seat directly, but...
Executives from the Democratic Party of Japan will not rule out penalizing party kingpin Ichiro Ozawa, including up to expulsion, if he refuses to give the Diet an explanation of the financial scandal for which he faces indictment, DPJ lawmakers said....this would certainly impair his ability to play factional games inside the party. That's important when you remember his reputation as the "Shadow Shougun" of the Democratic Party of Japan... the supposed kingmaker and faction sponsor without peer, and a man known for practicing some pretty brazen bare-knuckles politics.
It also doesn't interfere with indictment (above) that the Public Prosecutor's Office is working up, and if that does come to pass, then there is some hope that Iwate #4 will be electing someone other than Ozawa to the seat one day.
That's going to take a while, though. Suzuki Muneo (M. Suzuki) was convicted of his various misdeeds back in November, 2004, but he wasn't stripped of his seat until September of this year when appeals were exhausted.