Japanese Cambodia

Indonesian people call adenium as Japanese frangipani, perhaps associated with the circulating stereotype. For example, large fruits are commonly referred to as Bangkok, while small plants are commonly referred to as Japanese. Therefore, if a long time ago there was a frangipani whose plant figure was big and tall, then once there was a plant whose figure was small but similar to frangipani, it was called Japanese frangipani.

Actually frangipani is a type of Plumeria, a distant relative of Adenium. Some of the differences between Adenium and Plumeria are as follows.

Adenium stems are large with the bottom resembling a tuber, but the shape of the plant itself is small with long small leaves. Adenium roots can also enlarge to resemble tubers.
Plumeria small elongated stems without tuber shape, with a large plant figure and can grow tall, with long and large leaves. ^source