A restored Hien fighter plane was revealed to the media Oct. 13 ahead of it being exhibited from Oct. 15. Some parts such as the engine and switchboard are displayed separately from the body. (Yoshinori Mizuno)

KOBE--A rare fighter plane developed by a major Japanese motorcycle manufacturer 75 years ago during World War II has been restored as part of celebrations to mark the 120th anniversary of the company's founding.

Kawasaki Heavy Industries Ltd. revealed its refurbished technological legacy at an exhibition hall in the Kobe Port Terminal building on Oct. 13 in this city in western Japan.

The old fighter plane occupies an important place in the history of technological development within the company and influences today’s products including motorcycles and aircraft, according to the company.

The type 3-1 fighter, or Kawasaki Ki-61, was nicknamed Hien (flying swallow) and developed by Kawasaki Aircraft, a predecessor of Kawasaki Heavy Industries.

It made its first flight in 1941.

About 3,000 of the planes were produced during the Pacific War. It measured about 9 meters long, 12 meters wide at the wingtips and 3.5 meters in height. It weighed 3.8 tons. It was a relatively fast plane at the time, reaching 610 kph on the dial.

The restored aircraft is one of the Hien that were requisitioned by the U.S. military after the war ended and the last one remaining in Japan.

It had been on display at the Chiran Peace Museum in Kagoshima Prefecture in the southwestern island of Kyushu, from 1986 until 2015.

Suicide attack pilots flew out of the town of Chiran at the end of World War II.

The Kawasaki project team transported the aircraft to its factory in Kagamihara, Gifu Prefecture, the same factory where the body was originally produced.

The restoration process began in 2015 under the supervision of the Japan Aeronautic Association, the owner of the aircraft.

About 30 members volunteered and worked on the project on their days off and after work.

As most of the engineering drawings and other documents relating to the fighter plane were lost in the postwar chaos, the project team studied old photos of the Hien and documents of other aircraft from the same period kept at a British museum and other institutions.

About 80 percent of the instruments in the cockpit that had been removed were replaced by original parts from other machines acquired through auctions and private donations.

The engine has also been restored, but the airplane is not flyable.

“Staff that make the latest motorcycles also helped restore this aircraft,” said Toru Nohisa, a fellow of Kawasaki Heavy Industries, who oversaw the project. “I would like people to feel the passion of engineers who pursued speed (in the past and present).”

The exhibition of the Hien will open for the public at Kobe Port Terminal building from Oct. 15 until Nov. 3 between 10 a.m. and 5 p.m. Admission is free.

The aircraft will then join the collection at Kagamihara Aerospace Science Museum in Gifu Prefecture.

The company also announced that it has renovated Kawasaki Good Times World, a museum of its wide range of products-- motorbikes, a bullet train, ships and many more--at Kobe Maritime Museum, near the port terminal.