Until quite recently in rural Japan, yobai, or “night crawling” would have been an introduction to sex for many young people. While a young woman slept, a silent intruder would creep into her room, slide behind her and make his intentions known. If she consented, they would have discrete sex until the early morning, when he would have to slip out of the house as stealthily as he had slipped in.

The young man might be known to the girl and her family. Also, in a seasonal agricultural economy, farmers might have a number of laborers sleeping under their roofs sometimes, knowing that their daughters might be targets for yobai. In some cases, groups of friends would travel miles to neighboring villages, where the embarrassment of capture wouldn’t be as great, and each target a different girl.

In many cases, yobai would be conducted entirely with the knowledge of the girl’s parents. In fact, it was sometimes a prelude to marriage – parents would turn a blind eye the first few nights a young man secretly visited their daughter, but then he would be “caught”, and a more public courtship would begin.

Yobai tactics

Take your clothes off before you even sneak into the house. In Fukuoka, it was once illegal to attack a naked intruder, as he was probably engaged in yobai rather than theft.

In Fukuoka, it was once illegal to attack a naked intruder, as he was probably engaged in yobai rather than theft. Keep it quiet, even if socially questionable acts are required. One technique to avoid detection was to urinate along the bottom of doors to prevent them squeaking as they were slid open.

One technique to avoid detection was to urinate along the bottom of doors to prevent them squeaking as they were slid open. Practice safe sex. A night crawling man would often cover his face with a cloth, protecting himself and his chosen lady from embarrassment if she rejected his advances.

Yobai clubs

Reportedly, yobai still happens in the more remote areas of Japan, and there seems to be nostalgia for the practice elsewhere. The seduction of sleeping women is a popular theme of Japanese pornography, and some image clubs offer special yobai services – providing prostitutes who pretend to be asleep while the client slips into their futon.