渡辺明夫
is a Japanese adult visual novel developed by Petit Ferret with character designs by Akio Watanabe under the alias Poyoyon Rock. It was originally released as a PC game for CD-ROM on December 13, 2002 and subsequently re-released on DVD-ROM and for the PlayStation 2 with certain scenes removed. The title "Popotan" is a nonsensical word meant to reflect the prominence of dandelions, spelled in Japanese; Petite Ferret also produced a fan disc shortly before the DVD-ROM re-release. "Popotan" has been adapted to other media, including a novel series ("Popotan～ Himitsu no Jumon～ Kōhen") by Sassami Yachiruda; a manga series by Yūjiro Izumi; a twelve episode anime television series directed by Shinichiro Kimura, animated by Shaft, and licensed in North America by Geneon USA and later, Sentai Filmworks; a radio drama ("Poporaji"); and several art and reference books.