Night Bra - A Thing in Japan Apparently

I had never heard of a Night Bra until today when reading about the various commemorations on September 10th annually. Apparently, in English there is a term "Sleep Bra", which is more or less the same thing, but I had never heard of that either. Most people don't wear a bra at night in my home country, Ireland. In fact, I have never heard of anyone who wears a bra to bed, ever. 

However, thanks to Night Bra Self-Care Day ナイトブラでセルフケアの日 I came to realize that they are actually a major item in Japan. In essence it comes to two main reasons why the night bra is a thing in Japan: an old wives' tale and major beauty trend marketing.

According to some social media community posts I found, some people in Japan believe that not wearing a bra at night will make your breasts sag. They even have a saying for it "O-niku no maigo" (お肉の迷子): "stray fat". Women are told that if it isn't contained at night, the breast fat will literally wander off into the armpits and back. Ironically, in my homeland the old wives' tale is that wearing a bra at night prevents growth. You can see how both can influence a woman's choice to wear one or not.

The other reason that is widely reported is that in Japan brands heavily promote "bust care" (バストケア) through the use of "Night Bras".  Apparently, there are many advertisements promoting night bras. I have personally never noticed one. Reportedly the number one phrase they use is "yokonagare boshi" (横流れ防止), which means "preventing sideways flow." And they claim that not wearing a bra at night pulls the breasts to the sides permanently stretching the chest area out.

Another reason I saw for wearing a bra at night is to be ready for emergency evacuation. This reason actually makes more sense to me than preventing sag. Had you ever heard of a night bra or sleep bra before? Do you know anyone who wears them and / or are they common in your home country?