A gigantic weapon of destruction shrouded in complete mystery. When was it built, and where, and for what purpose? Nobody knows.

It has the form of a Haro, the mascot robot of the Gundam universe, but its cute form belies its extremely high performance.

It has a number of special weapons such as the Haro Drill, Haro Bubble, and Haro Bits, giving it overwhelming power on the field and earning it the nickname "Round Devil." But nobody knows what it really is...