The DPJ is center-left, the LDP is all over the place (due to its historical dominance of the political scene) but probably best described as center-right. New Komeito is conservative Buddhist but centrist otherwise. The minor Japanese Communist Party and Social Democratic Party that are also likely to win a few seats are obviously left-wing, and the breakaway People's New Party, a split from the LDP, is as murky in its ideology, though allied with the DPJ.
I'm no expert, but I also read/heard descriptions that both the LDP and the DPJ could be better desribed as "center-right to center-left parties"... so that both are neither right nor left (or very different from each other in terms of ideology, for that matter).
