Teruaki Masumoto, whose sister was abducted to North Korea in 1978, was heading for defeat in the four-seat Tokyo district.
Masumoto, 48, ran as an independent in a bid to swing public opinion against what he calls Japan's soft stance toward North Korea.
His elder sister, Rumiko, was abducted in 1978 from Kagoshima Prefecture at the age of 24. North Korea said two years ago she was one of eight abducted Japanese who had died. Five others returned to Japan in 2002.
However, Masumoto's efforts to keep public attention focused on the abduction issue apparently did not strike a chord with voters.
Muneo Suzuki, a former Lower House member on trial for bribery and other charges, was also set to lose.
Suzuki, 56, seeking a political comeback, ran in the two-seat Hokkaido district as an independent.
Former Tokyo Gov. Yukio Aoshima failed in his bid to stage a political comeback in the Tokyo district.
Running as an independent, the former television scriptwriter and screen celebrity was expected to suffer a second defeat after his unsuccessful campaign in the 2001 Upper House election.
