Gacky, also known as Ga-Keen, is a character from the Robot Girls Z universe, where she is a member of Team T, a group of heroes who protect the Earth by channeling the data and spirits of historical giant robots into human forms. Her design and origin are based on the classic super robot Magnerobo Ga-Keen.

Physically, Gacky is depicted as a teenage girl with purple hair that is cut to neck-length and gray eyes. Her typical attire includes a hairband and fingerless gloves, which complement her active and combat-ready aesthetic.

Gacky's personality is defined by her role as the "straight man" or tsukkomi of Team T. While she does not necessarily seek the position, she naturally falls into the role of the responsible one who must keep her often-eccentric teammates in check and manage their various antics. This leads to a life filled with constant worry and frustration, as she is perpetually burdened with looking after everyone else. Despite her exasperation, this dynamic highlights her underlying sense of duty and care for her team.

A significant aspect of Gacky's character is her passion for martial arts. She is a dedicated enthusiast and a serious practitioner of combat skills, drawing deep inspiration from the real-life kickboxer Andy Hug. This devotion to hand-to-hand fighting shapes her approach to combat and distinguishes her fighting style from other robot girls who may rely more heavily on their mechanical weaponry.

Within the story, Gacky fights alongside her teammates to defend Photon Power Town from various threats. She shares a particularly close bond with her fellow Team T member, Gai-chan, who is based on the robot Gaiking. The two are often seen working together, and Gacky has actively come to her aid in various situations. In one notable incident during a sports festival race, both Team T and Team Z were disqualified due to their aggressive tactics, which involved excessive destruction of the track and multiple rule violations. Gacky is also known to pilot a specialized multipurpose vehicle called the Delivery, which has the ability to shift between a motorcycle for ground travel and an aircraft for aerial missions, serving as a key piece of equipment for transport and combat.

In terms of mechanical abilities, Gacky has access to equipment referencing her original mecha form, including a weapon known as the Variant Anchor. Later in the Robot Girls Z ONLINE storyline, the character undergoes a significant evolution. Through a process called the "Team T Legend Plan," she can transform into a more powerful state known as Earth Gacky. This upgraded form grants her a completely new appearance, distinct knickerbocker-style attire, and a formidable pickaxe weapon, greatly enhancing her combat capabilities.