Kei cars are the smallest street-legal passenger cars, vans, and trucks in Japan. Known also as city cars, because they are economical in gas and fit in small parking spaces in the busy city. Kei cars are regulated to a specific size, power output and engine displacement.
Kei cars appeared after World War II when automakers in Japan noticed the drop in sales of full sized vehicles because they were out of reach financially speaking, for the everyday consumer.
Fast forward to modern day, they have been popular in Japan, with a highest popularity in 2013 when some 40 percent of new cars sold there were Kei cars! talk about popularity ! Nowadays some come with turbos, are FWD or AWD.
Kei cars are easy to spot in Japan, besides their small size , you can spot Kei cars by their license plate—they are black numbers on a yellow background.
Pictures : Our own
Info : https://www.motortrend.com/features/what-is-a-kei-car/