TV-Series
Description
Grenda-san is the oldest member of Robot Girls Team Z and is based on the powerful super robot Grendizer. Her background includes an air of mystery, as she is often referred to as a foreigner though her exact nationality remains unknown. She works and lives on Shirakaba Ranch in Nerima Ward, a detail revealed in the web manga adaptation. In terms of appearance, Grenda-san is a tall girl with a mature, buxom figure, standing half a head taller than her teammate Z-chan. She has long blonde hair and green eyes, which are usually depicted as closed during casual moments. Her battlesuit is designed to resemble Grendizer, featuring a black jacket with a red downward-pointing arrow on the chest, a red ascot, cuffs based on band-like armor, a red skirt, and dark blue knee-high boots. The top of her head includes the signature helmet and spikes of Grendizer.

Grenda-san is characterized as the most sophisticated member of Team Z, generally presenting herself as friendly, calm, and unfussy. She often serves as the serene and mature figure within the group. However, beneath this composed exterior lies a notable sadistic and vengeful streak. When she or her friends have been wronged, she harbors thoughts of punishing the offender in creatively embarrassing ways. These inner thoughts are described as so horrific and repulsive that they once caused a character to recoil in shock. Her motivations are rooted in a sense of justice and loyalty, as she has sworn an oath with her friends to bring peace, a sentiment she expresses before battle.

Within the story, Grenda-san is a core member of Team Z, the primary group of heroines dedicated to protecting Photon Power Town from various mechanical beast girls and other threats. Her role is that of a dependable and powerful ally who balances the more impulsive nature of her teammate Z-chan and the quieter demeanor of Gre-chan. Key relationships include her close friendship with her teammates, Z-chan and Gre-chan, as well as a notable admiration for Rhine X1, of whom she is a big fan. Her personal preferences are also demonstrated by her efforts to avoid listening to the singing of Belgas V5.

In terms of development, Grenda-san maintains a consistent personality throughout the series, though different adaptations and games explore additional facets of her character. In the online game, she can assume an enhanced form called Spazer Grenda-san, where she combines with her Spazer, gaining anti-gravity wings and new, powerful attacks. Another form, Roboiza-san, gives her the ability to control spacetime distortions, allowing her to influence past events. A humorous aspect of her character is her apparent tone-deafness; she shows resistance to loud and high-pitched sounds, including her own voice and the singing of Rhine X1, implying she is unbothered by noises that trouble others.

Grenda-san possesses notable abilities that mirror the powers of her mecha counterpart, Grendizer. She can change into her battlesuit using her Spazer, which also allows her to fly. Her combat capabilities include unleashing the Double Harken, performing attacks such as the Hanjuryoku Storm, and summoning the devastating Space Thunder. In her Spazer Grenda-san form, her abilities are heightened, and she can wield the Triple Harken as well as combine with her teammates to perform the Koshiryoku Beam Dynamic, a slow but immensely powerful sphere of energy.