Kei car is the smallest category of Japanese, expressway-legal motor vehicles. 'Kei' is diminutive for kei-jidōsha,, "light automobile" or "compact automobile". With restricted dimensions and engine specifications, owners benefit firstly from lower taxes and insurance rates which lead to a lower overall cost of ownership. And in most rural areas, importantly, they were also exempted from the general Japanese shako shōmeisho (車庫証明書) parking-space ownership requirement to legally buy a motor vehicle at all, as street parking is generally restricted in Japan. Japan's carmakers also make microvans and kei trucks within this legal category.

A microvan is a van or minivan which is within the Japanese kei car classification or similar, and is smaller than a mini MPV. In China, these vehicles are nicknamed miàn bāo chē because of their shape. Similarly, in several Hispanic American countries, these vehicles are called pan de molde, which means "bread loaf". In Indonesia, it is commonly called a minibus due to their tall roof, perceived as resembling a miniature bus; the term is also used generally to refer to any type of three-row MPVs.