The vehicle was originally developed by the Hope Motor Company of Japan in 1965 and sold as the HopeStar ON360. It used a Mitsubishi 360 cc (21 in³) air-cooled 2-stroke engine which produced just 21 hp (15.7 kW). It was a basic vehicle with no doors, but a sturdy four wheel drive system allowed it to go anywhere. The tiny Hope was unable to sell many of these vehicles and sold the design to Suzuki in 1968.
Suzuki's first move on acquiring the rights to the ON360 was replacing the Mitsubishi engine with a 359 cc (21 in³) Suzuki 2-cylinder which produced 25 hp (18.6 kW). The new unit was still below 360 cc, and Suzuki placed the spare tire inside the truck to keep it under 3 meters in overall length, allowing it to be introduced in 1970 as the first 4x4 keicar. The LJ weighed just 1300 lb (590 kg), but could scarcely reach 45 mph (72 km/h).
The LJ was updated for 1972 as the LJ20. The grille bars were changed from horizontal to vertical for the LJ20. The engine was swapped out for a water-cooled unit, and its 32 hp (24 kW) enabled the LJ to hit 47 mph (76 km/h). The introduction of left hand drive was a major switch and signalled Suzuki's worldwide ambitions for the truck. The Hard Top (Van) was also introduced. Suzuki did not export them to America, a US company called IEC (International Equipment Co.) imported them.
The LJ50, introduced in 1974 as the Jimny 550, SJ10, reflected the changing keicar rules. The engine was now a 539 cc (32 in³) 3-cylinder, though still a 2-stroke, and produced 33 hp (25 kW) and more low-end torque. The 1400 lb (635 kg) vehicle could now hit 60 mph (97 km/h), and the spare tire was relocated to the rear door, allowing for a fourth seat.
The final iteration of the original LJ design was the 1977 LJ80. Although the LJ50 remained in production, the new 1700 lb (770 kg) LJ boasted a 797 cc (48 in³) 4-stroke SOHC four-cylinder engine capable of 41 hp (31 kW). The additional power and torque of this engine allowed the differential and gearing to be raised for better cruising and offroad performance, and the track was widened by 4 in (100 mm).
The interior was also improved, with new seats and steering wheel. Metal doors were available for the first time in 1979, and a pickup truck model appeared that year as well. Though the LJ80 was retired in 1981.