The Seiun Award is a Japanese speculative fiction award given each year for the best science fiction works and achievements during the previous calendar year. Organized and overseen by the Science Fiction Fan Groups' Association of Nippon , the awards are given at the annual Japan Science Fiction Convention. It is the oldest SF award in Japan, being given since the 9th Japan Science Fiction Convention in 1970.

Japan Sinks is a disaster novel by Japanese writer Sakyo Komatsu, published in 1973.