A decision by the Tokyo District Court to reject a compensation case against a night club hostess who had a long-running sexual relationship with one of her clients effectively endorses adultery, experts say.

The ruling said the man’s wife was ineligible for compensation from the hostess because of the business motive for the relationship — to retain a good customer.

Similar suits in the past have awarded damages against a third party who had a sexual relationship with a married person, in what is considered a measure to support marriage.

The April 2014 ruling by presiding Judge Masamitsu Shiseki is discussed in the current edition of legal magazine Hanrei Times, which covers court cases. The magazine quoted judicial experts as saying it was the first-ever case to discuss the legitimacy of so-called makura eigyo, which roughly translates as “pillow sales tactic.”

“Makura eigyo” refers to a hostess maintaining a sexual relationship with a customer to ensure that he continues to visit the club regularly.

Some experts say the case may set a new precedent justifying extramarital affairs — as long as the third party is motivated by business interests.

In the lawsuit, the man’s wife demanded ¥4 million from the hostess for psychological distress. She alleged that the woman had conducted a sexual relationship with her husband, a company president, for over seven years.

But the court dismissed the claim, with the judge comparing the hostess to a prostitute, saying that the only difference is whether she received payment for sexual intercourse “directly” or “indirectly.”

As long as the intercourse is for business, it “does not harm the marital relationship at all,” the judge said.

The wife did not appeal the ruling, and the case was finalized.

Lawyer Katsuyuki Aoshima, who represented the wife in court, expressed strong concerns about the decision, calling it “a vicious precedent.”

“The judge did not need to introduce a new standard of allowing a sexual relationship outside marriage, introducing the word ‘makura eigyo’ out of nowhere,” Aoshima said.

He said neither defendant nor plaintiff had brought up the phrase in court. He added that the judge should have focused more on determining the facts, as the hostess denied having had sexual intercourse with the man.

“Without spending much time on confirming what happened, the judge concluded that the intercourse was a typical case of makura eigyo,” the lawyer said.

Aoshima said he fears the case may help weaken legal protections against adultery.

“Citizens should discuss whether compensation should be made by a hostess having a sexual relationship with a married man. A judgment like this case shouldn’t be set as a new standard without clear and logical reasoning,” he said.