Much remains mysterious about this ghost, because there scarcely exists any folklore, but the folklorist Kunio YANAGIDA says, '(Futon-kabuse) comes floating and abruptly covers a human's face until death,' in his book.
民俗学者・柳田國男の著書に「フワッと来てスッと被せて窒息させる」とあるのみで、伝承が少なく謎が多い。