The Dome F105 was an unraced Formula One car designed and built by the Japanese motorsport constructor, Dome. Dome was founded in 1975 by brothers Minoru and Shoichi Hayashi, who had built their first racing car ten years earlier. In 1980 the company built its first Formula Three car, and the Hayashi Racing team won the All-Japan Formula Three Championship in 1981 using its own 320 chassis. Dome first entered the Japanese Formula 3000 series in 1987, using a March chassis, but had plans to build its own chassis. Hayashi established a separate company, Jiotto Design, as a design department for Dome. As a result of this progress, Marco Apicella won the 1994 championship driving the Dome F104 chassis equipped with a Mugen Honda engine. Jiotto's facilities included a 25 per cent wind tunnel, computer-aided design and computer-aided manufacturing equipment, and several autoclaves: all of which could be used to design and construct a more complicated Formula One car.
The F105 was, like any Formula One car of its time, constructed around a carbon-fibre monocoque. It featured a conventional double wishbone suspension arrangement with pushrod-actuated dampers provided by Showa. Dome reached an agreement with Goodyear for tyres, although this was almost scuppered when the American company suspected that the F105 project was a ruse constructed by Japanese rival Bridgestone, which had announced its own intention to enter Formula One in 1997, to acquire information about its tyres.
The F105 was launched at the Spiral building in Tokyo on March 18, 1996. Marco Apicella, who had won the 1994 Japanese Formula 3000 championship with Dome, and local drivers Naoki Hattori and Shinji Nakano were selected as the project's test drivers. Apicella and Hattori both had brief experience of competing in F1, whilst Nakano was a Honda protégé who was driving for Dome in F3000. The F105 was tested for the first time at the Japanese Mine circuit in the spring of 1996, driven by Nakano, before the programme moved to Suzuka.
Dome's lack of sponsorship eventually forced it to cancel its plans to enter the 1997 Formula One season in the autumn of 1996. Nakano left the project and was promoted to Formula One with the Prost (formerly Ligier) team, which was equipped with Mugen engines. Sasaki attempted to obtain funding to compete in the 1998 season and beyond from a variety of sources, including the Nigerian Prince Malik Ado Ibrahim, who eventually invested in the Arrows team instead after negotiations with Honda for a fresh supply of engines fell through. The 1998 season also saw changes to the sport's technical regulations which rendered the F105 obsolete.