Flat Field Co., Ltd.

Flat Field Co., Ltd. (株式会社フラットフィールド) is a Japanese environmental engineering company headquartered in Atsugi, Kanagawa Prefecture. Founded in November 1995 by Tomokazu Hirano, who had previously run an automobile dealership in Osaka, the company was established with the aim of improving the environment. Its early work focused on eliminating PM2.5 emissions from diesel engines, and it became a pioneering specialist in converting commercial vehicles—especially trucks and buses—to cleaner fuels. Today it develops and manufactures electric vehicles, fuel-cell vehicles, hydrogen internal-combustion engines, natural-gas vehicles, and hybrid vehicles, and it also designs and builds engine test-bench equipment and gas-fueled generators. The company's core business is the research, development, and manufacture of low-emission vehicles, primarily through the conversion of mass-produced commercial vehicles. It has converted a wide range of models from Hino, Mitsubishi Fuso, Isuzu, Toyota, Nissan, Mazda, and Suzuki to compressed natural gas (CNG), and later expanded into electric buses, hydrogen fuel-cell vehicles, and hydrogen engine vehicles. Flat Field's CNG bus conversions were particularly notable in the 1990s and 2000s, when it split the small CNG bus conversion market with a competitor, Kabushiki Kaisha Kyodo. Its converted vehicles have been delivered to bus operators, municipalities, universities, and corporations across Japan, with cumulative low-emission vehicle deliveries exceeding 1,000 units. In recent years, Flat Field has shifted focus toward electric and hydrogen technologies in line with Japanese government eco-car policy. It has participated in numerous national and local government demonstration projects, including fuel-cell garbage trucks, hydrogen engine trucks, battery-swap electric logistics vehicles, and electric buses. The company is privately held, with capital of 95 million yen, and is led by representative director Tomokazu Hirano. Its main customers include electric and gas utilities, automotive manufacturers and dealers, transport and bus companies, government agencies, and universities.

Flat Field was founded in November 1995 by Tomokazu Hirano, who had previously operated an automobile dealership in Osaka. The company was established with the goal of improving the environment, initially focusing on eliminating PM2.5 emissions from diesel engines. Its first commercial product was a CNG-converted small garbage truck, launched in October 1997. In 1998, the company began converting buses to CNG, modifying two Mitsubishi Fuso Aero Midi MKs for Kyodo Kanko Bus. This marked the start of Flat Field's significant role in the small CNG bus conversion market, where it competed primarily with Kabushiki Kaisha Kyodo. Throughout the 2000s, Flat Field converted numerous bus models, including the Hino Rieesse, Mitsubishi Fuso Aero Midi MJ and ME, and Hino Rainbow HR, for community bus services across Japan, including in Suginami, Higashimurayama, Koganei, Fuchu, Chofu, Saitama, and Kokubunji. The company also converted trucks and vans for various clients. In 2000, body conversion for Flat Field's CNG buses was taken over by Yanase, giving the vehicles a distinctive straight-line design for the roof-mounted gas cylinder cover. By 2006, Flat Field had delivered over 100 community buses and 850 CNG vehicles cumulatively. As emission regulations tightened and diesel technology improved, the market for CNG buses declined. Flat Field shifted its focus to electric and hydrogen vehicles. In 2009, it manufactured a hydrogen fuel-cell bus based on the Hino Rieesse in collaboration with Tokyo City University and Hino Motors, which became Japan's first hydrogen bus to receive a license plate for public road use. In 2012, a Flat Field-converted hydrogen bus entered demonstration service with Yamanashi Kotsu, the first commercial operation of a hydrogen bus in Japan. The company also developed electric buses, including microturbine hybrid buses for Hinomaru Jidosha Kogyo and LPG hybrid buses for Kaetsuno Bus. In the 2010s and 2020s, Flat Field continued to participate in government-backed demonstration projects. It delivered electric buses to Waseda University, Suntory, and various municipalities. In 2023, a fuel-cell garbage truck jointly developed with Waseda University and the Tokyo Metropolitan Government began trial operation in Tama City. The company also received adoption for projects involving hydrogen internal combustion engine excavators and hydrogen supply infrastructure. As of the 2020s, Flat Field remains a privately held company headquartered in Atsugi, Kanagawa, with cumulative deliveries of over 1,000 low-emission vehicles.

• Company founded in Shibuya, Tokyo.

• First commercial product: CNG-converted small garbage truck.

• Started CNG conversion of buses; delivered two Mitsubishi Fuso Aero Midi MKs to Kyodo Kanko Bus.

• Yanase took over body conversion for Flat Field's CNG buses; development center established in Higashimurayama, Tokyo.

• Began CNG conversion of Hino Rieesse; first route bus delivered to Keio Bus Higashi for Suginami Ward's 'Sugimaru' community bus.

• First non-step CNG bus conversion: Odakyu Bus Aero Midi MJ with roof-mounted cylinders.

• Cumulative deliveries reached 100 community buses and 850 CNG vehicles.

• Manufactured Japan's first publicly road-legal hydrogen fuel-cell bus based on Hino Rieesse, in collaboration with Tokyo City University and Hino Motors.

• Hydrogen fuel-cell bus converted by Flat Field began demonstration operation with Yamanashi Kotsu, Japan's first commercial hydrogen bus route.

• Fuel-cell garbage truck trial operation started in Tama City, Tokyo, with Waseda University and Tokyo Metropolitan Government.

Specialist in low-emission commercial vehicle conversion and development, with a focus on CNG, electric, and hydrogen technologies.

• CNG-converted buses (Hino Rieesse, Mitsubishi Fuso Aero Midi, Hino Rainbow HR)

  Buses converted to run on compressed natural gas, widely used for community bus services in Japan.

• Hydrogen fuel-cell bus (Hino Rieesse)

  Japan's first publicly road-legal hydrogen bus, developed with Tokyo City University and Hino Motors.

• Electric buses (Hino Poncho, Isuzu Erga)

  Battery-electric buses delivered to universities, municipalities, and corporations.

• Microturbine hybrid bus

  Series hybrid bus with microturbine, used for Marunouchi Shuttle and Metro Link Nihonbashi.

• LPG hybrid bus

  Japan's first electric bus with LPG-fueled generator, delivered to Kaetsuno Bus.

1. 1株式会社フラットフィールド｜電気自動車,電気バス,天然ガス,水素燃料自動車などの研究flatfield.co.jp
2. 2会社沿革 | 株式会社フラットフィールドflatfield.co.jp
3. 3会社概要 | 株式会社フラットフィールドflatfield.co.jp
4. 4フラットフィールド - Wikipediaja.wikipedia.org
5. 5Flat Field - Wikidatawikidata.org