Not quite. The DPJ survived the 2006 Koizumi landslide to hold on to four out of the four-and-a-half Nagoya seats* in the Lower House. The DPJ also holds four out of the six Upper House seats allocated to Aichi Prefecture. Thus, fifth-term Lower House member Takashi Kawamura of the DPJ was not taking much of a risk to vacate his Aichi First District seat to run, successfully as it turned out, for mayor of Nagoya. The DPJ’s only worry was Ichiro Ozawa, whom it stashed away in the closet during the campaign.
I might have more to say after I see the final tally, but that’s what it is—nothing more, nothing less.
* The LDP has one seat that consists of two other cities and parts of Nagoya. For Aichi Prefecture as a whole, the LDP holds a nine to five edge in single-seat districts.