The Ao-andon, or Blue Lamp Ghost, represents the spirit which appears during the Hyaku monogatari, or "hundred stories." In the Edo period, the Hyaku monogatari was a popular past time, in which a crowd would gather to tell ghost stories. The room would be lit by 100 candles in andon lamps, surrounded by blue paper to create an eerie atmosphere. After each story was told, one candle would be put out. After the last story was told, the room would be consumed in darkness and it was said the Ao-andon would appear.