There are 2 types of car licence plates in Japan,one is white and the other is yellow in colour. The white one is applicable to cars over 1,000cc and the yellow plate is lower than 1,000cc. The yellow plated cars are known as " K " or karui which means "light vehicles". "K" plated cars are lower in taxes etc and in some places have dedicated or specially allotted parking lots. Most " Ks" are used as second car in the family.
In Japan, the number of vehicles owned by a family are determined by the number of car parking lots they have.
Most, if not all public car parking are free of charge except in the cities and at train stations.