A mobile suit for ground combat that was developed at the same time as the J-type, the MS-06 Zaku II’s version for use under gravity, achieving superior mobility while being more heavily armored than the Zaku. Two versions of the YMS-07, a blue and khaki color, are displayed in the mobile development chart below. The chart illustrates that the YMS-07 Prototype Gouf Tactical Demonstrator comes from two broad development lines.

Depicted above is the MSV version of the YMS-07 Prototype Gouf,  a mobile suit for ground combat to replace the Zaku. Lacking the internalized weapons in both arms that are characteristic of the Gouf, the arms are a standard variety just like the Zaku. The structure of the cockpit hatch, the head and chest, the power pipes around the abdomen, the knee pads and the like are different from the standard Gouf. The YMS-07 is characterized by the design of its all-view mono eye and backpack. Three nozzles in a row on the backpack and a square block like the helium core of the RX-78 are rare on Zeon mobile suits.

The YMS-07 is well known in the old MSV setting and has been updated accordingly for the world of the Origin. The shape of the body was designed based on the MSV model. In terms of coloring variation, in addition to the khaki color suit that references the color sketch from the MSV series, there is also a suit that is painted blue, which is Ramba Ral’s color. Unlike the khaki colored suit, the blue suit is not painted white on the upper arms and thighs and the overall appearance of is very close to the Gouf from First Gundam. The blue design depicted above was the initial sketch of the Prototype Gouf prior to a model number being assigned to it. The finalized design version is listed below with the markup coloring on it. Katoki, the designer, modified the design slightly to mirror the white portions present on the khaki colored suit to the blue. This was because it was a pattern that was prevalent in MSV and MSX.

The blue version is the same type of unit as the khaki prototype Gouf. This configuration is utilized by the same development team. The four digit numbers denoted on the center of the chest and on the toes are a reference to the markings from the MSV version. The four digit numbering is different for each of the three units introduced this time. The numbers are as follows. Because the numbers are different on all suits, it is safe to assume that the mobility demonstrator and tactical demonstrator are separate entities.

MOBILITY DEMONSTRATOR (BLUE): 8125
MOBILITY DEMONSTRATOR (KHAKI): 8126
TACTICAL DEMONSTRATOR: 8127

This suits design follows the old MSV markings and coloring. Markings were applied after correcting the details of the backpack on the rear. A feature of the MSD version of the Prototype Gouf is to carry the Origin version of the MS-04’s machine gun. The characteristic linear markings all over the frame were intentionally made somewhat larger to give it a retro feel. Because the Prototype Gouf itself minor in the MSV series, consideration was made so that the khaki colored version would not be very different from the impression the source material gave.

As a test type that modified the YMS-07, the right forearm is replaced with a heat rod and the left forearm is replaced with a built-in machine gun. Although it only existed in the MSV setting, the suits following Prototype Unit 3 of the YMS-07 were equipped with built-in weapons in both arms, a special new approach the Origin put together. Minor changes to the YMS-07 has both arms replaced with built-in weapons. As a suit that existed solely for testing internalized weaponry, the manipulators were left off. The design gives it a clear sense of being a test type. The artwork depicted above illustrates the suit without markings.

Making use of the interchange gimmick of the forearms of the Mobile Worker, module swapping capabilities have been added to the arms of the YMS-07. It is structurally feasible to attach the forearms meant for the Mobile Worker.

Once the overall design of the Mobile Worker was decided on, details on the detachable system of optional parts as a gimmick for the arms was narrowed down.

When compared to the markings on the Mobility Demonstrator, the impression left by this suit is has fewer lines and is more refined. The color scheme of the upper arms and thighs is blue and, unlike the other prototype Goufs, this version is closer to the First Gundam Gouf. The cross-shaped geometric patters on the center of the thighs was designed with a line pattern as a motif that was also found on MSV markers. The suit number “31” that is found on various places all over the body can be seen on the left side of the chest and left shoulder on Ral’s Mobile Worker MW-01 Model 01 Late Type. Ramba Ral is a pilot of this particular Tactical Demonstrator as indicated with the number on the suit. While the blue may be his color, he is not the pilot of the other blue Mobility Demonstrator.

It would seem that the structure of swapping the forearms for mounting new weapons on the Tactical Demonstrator, which was developed with the Mobile Worker, was quite helpful. Like the Gouf that would follow, it mounts a heat rod on the right forearm and machine gun to the left forearm.

The MSV version of the YMS-07 emulates the form of the chest, front skirt, and knee pads, but the details of the soles and underarms reflect the Origin version. The cockpit hatch design is unique to the Prototype Gouf. The MS-07H type is also this type.

In the sketches above, the parts with different configurations between the Mobility Demonstrator and Tactical Demonstrator are shown in green. They are essentially the same except for the shape of the forearms. When utilizing the interchange system of the forearms, it is possible for the Tactical Demonstrator to be equipped with standard manipulators. The five finger manipulators already implemented on the Mobile Worker can be utilized.
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An extendable whip-like fighting weapon. Wrapping around a target and letting the top latch on, damage can be inflicted by adding an electric shock. It was designed based on the Origin version of the Gouf. As the design characteristics are inherited from the Origin version, the tip of the rod splits into four parts. The shape of the rod is essentially considered the same for both the YMS-07 and the MS-07B.

The Origin version has a characteristic drum-type forearm. In the comics, the heat rod is slightly narrower versus the one from First Gundam. The forearm part from First Gundam is not much different from the Zaku in terms of size.

Conceptual diagram of the head rod’s gimmick. The sketch on the left shows the heat rod completely stored in the forearm. The sketch on the right shows the rod being fired. The entire rod rotates as it is being released.

The forearm that houses the heat rod emulates the drum-type of the comics and has a larger capacity than the Zaku’s forearm. Even when the heat rod is completely contained, the tip portion of the rod is exposed. It is experimental equipment for trial of the heat rod so manipulators equipped on general mobile suits has been omitted. The far right art is a draft version of the heat rod in storage. The shape of the tip part is somewhat different from the final version.

A solid round type of heavy weapon built into the left forearm. Magazines are attached to the front side. In the Origin version, the barrels are drawn in an elongated fashion and it is designed to easily grasp objects. In First Gundam, the barrels are drawn thick and short like fingers. A variation of the Gouf equips the magazines on the forearm. The Origin version of the Gouf seems to interpret part of the elbow pad part as a magazine.

The magazine is designed to imitate the elbow bad of the Origin version of the Gouf. It hints at being related to Ral’s MS-07B. Both sides of the gun barrel base is asymmetrical in design. Much like the heat rod, the forearm is a drum-type design which differs from both the First Gundam version and the Origin version. Three gun barrels and sensors were designed to be like fingers, but they do not have function as manipulators. The image of First Gundam is reflected in the thick, short barrels.

Unlike the Zaku, it is equipped with a detachable shield for its left hand. Although the mass produced Gouf stores a heat sword on the back of the shield, the YMS-07 is equipped with a heat hawk instead. The First Gundam version and the Origin version designs of the shield are essentially the same. The MSD version was designed based on the Origin version (as seen below).

The heat sword, which is the Gouf’s hand-to-hand combat use equipment, is regarded as being a real sword blade, but in First Gundam it was shown to look like a beam saber. The comics also followed this direction.

The shape of the exclusive shield isn’t much different than the Gouf’s shield but instead of there being a heat saber stored in the back there is a heat hawk. The marking of a number 2 on the khaki color Mobility Demonstrator shield emulates the MSV version. Single digit markings can be confirmed on other prototype mobile suits so it can be assumed there is a standardized rule. Although not drawn with it, the Tactical Demonstrator is capable of using the same shield as the Mobility Demonstrator.

In the MSV version, the YMS-07 is equipped with a standard Zaku machine gun, but the MSD version of the Mobility Demonstrator carries the MS-04’s machine gun from the Origin. The machine gun, which is a portable weapon, fires solid rounds and its body is tailored to handle tank cannons and even mobile suits. Depicted above is artwork of the side grip and stock deployed. An ejection  port is provided on the right side.