Did you ever get the feeling that most cars in Japan look kind of boxy and cubic? Like rolling boxes, trying to be as space-efficient as possible? That’s because in japan there is a breed of cars that is supreme common but rarely seen elsewhere, especially not in the Western Hemisphere: the Kei car or Keijidousha in Japanese (軽自動車).

Kei car is a Japanese category of small vehicles, including passenger cars, microvans and really small pickup trucks.

They are designed to comply with Japanese government tax regulations, and in most rural areas are excluded from the requirement to certify that parking is available for the vehicle. This especially advantaged class of cars was developed to popularize motorization after the war. Even though it is quite successful in Japan, the genre is generally too specialized and too small to be profitable in export markets.

The kei car came along in the times following the end of the Second World War, when most Japanese could not afford a full-sized car, yet had enough to buy a motorcycle. To promote the growth of the car industry, as well as to offer an alternative delivery method to small business and shop owners, Kei car standards were created.

The cars feature yellow license plate, earning them the name “yellow-plate cars”in English-speaking circles. Because regulations only restrict physical size and engine displacement, manufacturers have been able to introduce many advanced technologies to the class. 

Even though the classical Kei car gets smaller and stronger every year due to new regulations and laws, there is an electric alternative as well: Mitsubishi Motors introduced an electric kei car in 2010 to the general public. The car in Japan is called the i-MiEV, an acronym for Mitsubishi innovative Electric Vehicle. Current models charge overnight in 14 hours from home 110-volt mains, making them convenient city cruisers to get to work and charge them overnight.

Next time you walk around the city, try to spot as many yellow number plates as you can!