Zetton recurs throughout the *Kaiju Girls* anime series as a female humanoid embodiment of the Ultra Series kaiju. Her origins are shrouded in mystery, with no birth date or real name revealed in official media. Affiliated with the organization GIRLS, she holds the title of current champion in the "Big Kaiju Battle" competition and is recognized as the strongest kaiju girl within the group.

Visually, Zetton possesses long black hair and striking yellow eyes. Her personality presents as cool-headed and reserved, yet she demonstrates distinct concern for fellow kaiju girls, particularly Aki Miyashita (Agira), observing that Aki resembles her younger self—implying shared struggles. A subtle layer to her enigmatic demeanor, revealed in the anime's second season, is her habit of taking selfies.

Her formidable abilities derive directly from the original kaiju, granting her superhuman strength, teleportation, and barrier generation. Zetton employs these powers creatively, such as extinguishing fires by enclosing and compressing flames within her barrier. Her unmatched combat prowess solidifies her championship status within GIRLS.

The spin-off manga *Galaxy Days* depicts Zetton as a student at Tsuburaya School and identifies her as the younger sister of Alien Zetton, adding familial context absent in the anime without elaborating on her origins.

Across all media, Zetton maintains an aura of mystery. Her activities beyond GIRLS duties and championship battles remain undisclosed to most characters, and her real name stays unrevealed. Her character development centers on subtle mentorship towards Aki and the consistent portrayal of her unparalleled strength.