The woman in her 20s was found with her hands and legs bound with ropes and belts at her apartment in the capital's west on Monday, the Sankei Shimbun said.
The apartment owner discovered her unconscious but otherwise unhurt, the newspaper said, adding that the landlord called the police and the ambulance, fearing the woman had been the victim of a vicious home robbery.
But detectives grew suspicious of the young tenant's story when they failed to turn up any evidence of forced entry to the flat.
During questioning, the woman broke down and admitted there was nobody else involved. "I did not want to go to work, so I did it as an excuse for absence without due notice," she told officers, according to the paper.
Police, who declined to confirm the report, issued a reprimand but decided the woman should not face charges.