Kamen Rider G3
One of the secondary Riders on Kamen Rider Agito
Designed by the genius Ozawa Sumiko to combat the Unknown Lifeforms from Kamen Rider Kuuga. Despite the lack of appearance of Unknown Lifeform for a period of time, the G3 Project was completed and added to the active police force.
Kamen Rider G3
Main user: Hikawa Makoto
Other Users: Houjou Tooru, Tsugami Shouichi
While initially near useless against the Unknown, with a few modifications and upgrades, the G3 System was eventually able to take down Unknown without Agito's help.
Kamen Rider G3-X
While not necessarily a powered up version, it is a graded up model of the G3 System and shares the same user.
His belt shows his current energy level. The helmet portion contains a camera.
Kamen Rider G3 Mild
G3's Arsenal
1-5
G Trailer
Manager: Ozawa Sumiko, the designer for the G3 System.
Operator: Omuro Takahiro
Since the G3 System is essentially a power armor, Hikawa does not transform like most other Riders. He never shouts "Henshin". In fact, he gets the suit put on him in the G Trailer. When he's done equipping the armor, he is launched out the back of the G Trailer on his bike, Guard Chaser. (Sort of like Captain America out of his van from the TV movies.)
When in battle, G3 is always in contact with the G Trailer. The support staff gives orders and assistance, as well as activating G3's various weaponry for him.