ナイトガウン

Also known as sleepshirt

thumb|A modern men's nightshirt A nightshirt is a garment intended for wear while sleeping, often with a nightcap. It is longer than most regular shirts, reaching down below the knees, leaving some of the legs uncovered. It is often referred to as a nightgown for men, but nowadays, nightshirts are an optional sleepwear for women too.