In Japan, costuming at conventions was a fan activity from at least the 1970s, especially after the launch of the Comiket convention in December 1975. Costuming at this time was known as . The first documented case of costuming at a fan event in Japan was at Ashinocon (1978), in Hakone, at which future science fiction critic Mari Kotani wore a costume based on the cover art for Edgar Rice Burroughs' novel "A Fighting Man of Mars". In an interview Kotani states that there were about twenty costumed attendees at the convention's costume party—made up of members of her "Triton of the Sea" fan club and , antecedent of the Gainax anime studio—with most attendees in ordinary clothing. One of the Kansai group, an unnamed friend of Yasuhiro Takeda, wore an impromptu Tusken Raider costume (from the film "Star Wars") made from one of the host-hotel's rolls of toilet paper. Costume contests became a permanent part of the Nihon SF Taikai conventions from Tokon VII in 1980.