I made mention of the practice of Yobai in a post on sneak masks last year. Yobai is an old custom in Japan in which a man would visit a woman at night to have sex. The practice went like this: A young woman would be sleeping in her room and a guy would creep in, slide behind her, and make his intentions known. If she consented, they would have discrete sex through the night, with him then slipping out of the house stealthily before anyone woke up. While sometimes it was just a sexual romp, quite often the girls family would know about it. It was occasionally seen as a prelude to marriage, the first few nights a young man secretly visited their daughter the family would pretend nothing happened, then they would catch him and a public courtship would begin. This practice would also occur between married couples as it was not unusual for wives to continue to live with their parents.
This practice is now seen as an immoral one and for the most part is not done, several decades ago it was still done in some rural areas, but was not common. It has not died out entirely though. The seduction of sleeping women is a common theme of Japanese pornography and some places offer yobai services (prostitutes who pretend to be asleep while the client slips into their futon). Yobai can be seen in Japanese literary works like The Tale of Genji. It also is sometimes mentioned in manga and anime, for example in the Ah! My Goddess TV series Keiichi approaches Belldandy's room wondering if he is doing a form of yobai.
- A night crawling man would often wear a tenugui (cotton cloth) over part of his face. In part to protect his identity if she rejected his advances and so that she could honestly state that he was wearing a mask (therefor she is unable to identify him).
- A technique to help avoid detection that was used, was to urinate along the bottom of doors to prevent them from squeaking as they were slid open.
- Sometimes the guy would take his clothes off before even sneaking into the house. This was done so that the person, if caught, would not be mistaken for a burglar (this was legal sometimes and places, theft still wasn't).
- Originally the term came from the verb yobu, meaning to visit. Overtime it came to be written with the kanji for night and crawl.
Obligatory Ranma reference (seeing as to how that is a theme of this blog). In the second volume of the manga (VIZ count), Ranma sneaks into Akane's room because Ryoga in pig form is sleeping with Akane. Everyone in the house thinks that Ranma's attempting Yobai. The comments all support this with Nabiki saying to do it quietly, Soun saying it shows Ranma's healthy, and Kasumi thinking it is not right to do.