The ruling Democratic Party of Japan was quick to rule out a shakeup of DPJ executives over the defeat in the Upper House election, but Defense Minister Toshimi Kitazawa and other members indicated Tuesday someone should be held responsible.

"The DPJ went into this election as a whole and I think (someone) needs to take responsibility for the defeat," Kitazawa told reporters, indicating that otherwise it would be hard to feel a sense of crisis over the party's setback.

Some DPJ lawmakers have said Secretary General Yukio Edano should step down, but Kitazawa refused to single out the individual ultimately in charge of the party's election management. The defense minister, however, was quick to say Prime Minister Naoto Kan should remain in his post.