Warai onna live deep in the mountains of the island of Shikoku. Their distant laughter is often heard late at night by woodcutters and travelers who find themselves in the mountains past dark. Despite their non-threatening appearance, warai onna are quite dangerous. Those who travel into mountains where warai onna live risk their lives. Upon meeting a warai onna, she will smile and laugh at a person. Their laughter is infectious, and often causes those who meet them to laugh along too.