Principality of Zeon is based on "MS-06F Zaku II" for space that was completed as a highly versatile aircraft to respond to Earth invasion strategy, "MS-06J" which becomes an under gravity specification with improved legs etc. Production. From here, the Zion army will focus on developing MS under gravity.
Following the minor change version of the "MS-06J", the "MS-07B GOUF" was developed, which was more specialized for land combat and was designed for close combat with upcoming Federation MS. However, at this stage, the shortcoming of the MS's poor mobility under gravity had not been resolved, and this was a major issue in the development of the MS.
Zimat Co., which had decided to adopt the formal adoption in the mass production MS development competition with Geonic, was trying to kill himself by solving the problem of moving speed of MS.
Zimmat was contracted to produce the MS-07B GOUF under license, and based on that, they completed the YMS-07C-5 GOUF TEST PROTOTYPE, which incorporated improvements to its high-speed movement capabilities, and collected operational data. Based on that data, they equipped the legs with thermonuclear jet engines to give it hovercraft capabilities, completing the YMS-09, later known as the Prototype Dom.
With the function to float and propel the aircraft by the hovercraft, it gains more than twice the moving speed compared with the conventional MS. Furthermore, battle in wetlands and lakes where movement is restricted by bipedal walking is also possible and showed the possibility of widening the range of MS operation on the ground. In addition, with the improvement of the moving speed, the giant buzz with high attack power assuming base attack etc. by MS alone, and the heat saber easy to perform attack against MS while moving at high speed were equipped.
Zeon home country = two side prototypes developed at Zimmat headquarters in side 3 were sent to California base which is the important base of the North American front line at the same time of completion, and started practical test.
As the prototype was already in the stage of completion of the usefulness was already expected to be useful, Colonel Frederick Cranberry who was famous as an ace pilot as a test pilot, proved the high performance in practical tests, Acquired the seat as machine.
Later, as a result of redesign of exterior materials and equipment, mass production started as "MS-09 Dom" in a few weeks, and MS operation on the ground was changed dramatically.
Then, "YMS - 09 Prototype Dom" who finished his role will be given a new start as a research mother of MS - 09 for tropical battles.