The Carnal Prayer Mat or Rouputuan (Chinese: 肉蒲團; pinyin: ròupútuán; also known as Chinese: 迴圈報; pinyin: huíquānbào) is an erotic novel written by author Li Yu (李渔) in 1657 during the Qing Dynasty. It is divided into 4 chapters: Spring 春, Summer 夏, Autumn 秋, Winter 冬. It was brought to Japan in 1705 where it is known as nikubuton (肉蒲團/にくぶとん). The novel was used as the basis for Hong Kong Category III films Sex and Zen and 3D Sex and Zen: Extreme Ecstasy.[1]