Some people say that it started when someone threw a fan at a butterfly which was resting on a wooden pillow, and found it amusing to see the butterfly and fan floating in the air and landing on the wooden pillow.
由来の一つとして木枕に蝶が休んでいる所に扇を投げつけた所その蝶と扇が舞い、木枕に乗る様子がおもしろいとしたというものがある。