The difference between a Japanese holly and a holly is that a Japanese holly is a holly, except that it is one specific type of holly. All holly plants come from the genus known as Ilex. The botanical name that follows the genus indicates the specific holly species or type. For example, the Japanese holly goes by the botanical name Ilex crenata. Visually, what makes the Japanese holly species different than other hollies is that the Japanese holly has small round leaves and dark black fruits. By contrast, many popular hollies have red fruits and leaves with more complicated shapes.