are (supernatural beings) in the folklore of KÃ Âyama, Kimotsuki District, Kagoshima Prefecture (now Kimotsuki). They are also called or .
According to the , jointly authored by the locally born educator Nomura Denshi and the folkloricist Kunio Yanagita, at evening time, a cloth-like object about 1 in area (about in length and in width) would flutter around attacking people.
They are said to wrap around people's necks and cover people's faces and suffocate people to death, and in other tales it is said that wrapped cloths would spin around and around and quickly come flying, wrap around people's bodies, and take them away to the skies.
There is a story where one man hurrying to his home at night when a white cloth came and wrapped around his neck, and when he cut it with his (short sword), the cloth disappeared, and remaining on his hands was some blood.
In regions where they are said to appear and disappear, there seemed to be a custom where children were warned that if they play too late, that " would come."
Also, it is said that in Kimotsuki, there are shrines (the for example) where are said to frequently appear, and it was believed that when children pass in front of the shrine, an flying above in the skies would attack the last child in line, so children would go run ahead and cut through.
In the classical , the , there is a shaped like a cloth with arms and legs. The folklorist hypothesizes that this is the origin of .
According to a report from the yà Âkai researcher , there have been claims of flying cloth-shaped objects said to be .
In Kagoshima Prefecture there are claims that white cloth-like objects have been seen flying in low altitude. In Fukuoka Prefecture and in Kyushu there have been claims of extremely speedy flying alongside trains witnessed by passengers.
Outside Kyushu there have been claims in Higashi-KÃ Âenji Station and Ogikubo, Tokyo. In Higashi-KÃ Âenji, a woman walking her dog said she saw a cloth flying in the skies.
In Shizuoka Prefecture, elementary school kids were said to have seen a transparent sheet-like object flutter around.
While filming , the actor Shirà  Sano said he saw an flying above with a long white shape.
are thought to appear in the evening, but the general view is that this is because in the past, parents needed to do farmwork for the entire day including at this time and therefore could not keep an eye on their children, so the tales of were told to children to warn them of the dangers of playing too late. Also, in the lands where the legend is told, there is a custom of raising a cotton flag during burials for the purpose of mourning, so it is inferred that some of these would be blown by the wind and fly in the air and thus be connected to the legends of the .
In the Japanese television series there was an experiment performed in which a piece of cloth about long was set up and moved in the darkness, and the average length reported by the people who saw it was , with the longest being . The program suggested that when a white or bright objects move in the darkness, a positive afterimage optical illusion would leave a trail due to movement, causing soaring things in the forests at night such as to be seen as longer than they actually are, and thus mistaken as .
There are no depictions of ittan momen in classical yà Âkai emaki, so these yà Âkai was once relatively unknown, but they have become more widely known since appearing in Mizuki Shigeru's manga GeGeGe no Kitarà Â. This manga depicted them as speaking a Kyushu dialect, having good-natured personalities, and having a unique look while flying, which raised their fame and popularity despite their original legend of attacking people. In Mizuki's depictions these yà Âkai are depicted as a cloth with two eyes and two arms, so now they are commonly perceived to be pieces of cloth with two eyes in yà Âkai depictions, but Mizuki's depictions are original inventions and the ones in actual legend and in the previous witness reports have no eyes or arms and are instead simply flying objects that resembled cloth. In Mizuki's birthplace, Sakaiminato, Tottori Prefecture, they ranked number 1 in the "First Yà Âkai Popularity Poll" held by the tourism association.
In Kamen Rider Hibiki they appeared as enemy characters and they were based on the original legend with some extra original twists on their appearance and personality.
In 2007, the local historian of Kagoshima Prefecture, Takenoi Satoshi, started creating kamishibai of ittan momen so that such legends that are gradually being forgotten can be remembered by the children.
In the 2020 anime adaptation of the In/Spectre ("Kyokà  Suiri") novels, an ittan momen drawn in the Mizuki style, flies out from under the skirt of the female protagonist Kotoko.
The following are yà Âkai considered to be similar to ittan momen. The musasabi would glide through the air along forest streets at night and cling to people's faces in surprise, so it is theorized that they are thought to have inspired a yà Âkai like this.
Fusuma ("bedding")
Futon kabuse (literally, "cover with futon")