Fujita Iron Works (Naka Ward, Nagoya City), 1948-59
Jos Creusen in The Netherlands did a nice write-up in Dutch on the Fujita Iron Works motorcycle called the Auto Bit ( オートビッ ), which I paraphrase here in English:
"AutoBit motorcycles were produced by Fujita Iron Works. Before the Second World War it was a firm with some 50 employees specialized in the manufacture of gearboxes and located in the vicinity of Naka-Ku, Nagano. During the mobilization of Japan and during the war a second factory was opened, intended for the production of ammunition in the Nakagawa District. Towards the end of the war, the facility was moved to the east of Japan in Ibi-Gun.
After the war the Nakagawa District location was opened again. As production of items that could be used for war purposes wwas prohibited, work was started on the production of wood processing machines.
In 1948 the first prototype of a motorcycle was produced. The designer of the engine was Miyazaki Kyosuke, who had worked for Mitsubishi Nagoya Movers Works during the war. He was responsible for the design of the Mitsubishi engine blocks that were mounted in Mizuho and Olympus frames. At a later stage he was responsible for the design of the OHC engine blocks of the Pearl motorcycles.
The first real motorcycle, with 2.5hp and 2 speed gear box with hand change, appeared in 1950. Despite the fact that the frame was clearly too weak for the engine, it sold well.
Fujita Iron Works was registered at the Japanese exchange in 1952 and then had 115 employees. Engine blocks and frames were their own production and other components were brought in from local suppliers.
In 1952 there was only one model which was an OHV single cylinder of 150cc. In 1953 the 150cc was increased to 4hp and the frame was reinforced. A 250cc FE model was also released with 5hp."
I have not been able to confirm this, but motorcycle manufacturing appears to have ended at the same time as the Ise Bay Typhoon of 1959 which devasted that area of Japan. The Fujita Iron Works company does appear to still exist today supplying parts to Yamaha, Tohatsu Marine and STIHL amongst others.