Tomomi Okada, recurring under her kaiju identity Pigmon, stands as a founding member of GIRLS alongside Makoto, her involvement dating to the group's inception as implied in "The Beginning Stories". Her friendly demeanor, marked by a near-constant smile, occasionally conceals flashes of intensity or intimidation. She cuts a distinctive figure with her small stature and very long red hair, often styled in pigtails.

As a kaiju girl, her abilities remain notably limited, inheriting the original Pigmon's non-combat nature. Beyond the baseline superhuman strength shared among kaiju girls, she possesses no special combat powers and tires exceptionally easily, even during routine activities like sports training—a consistent trait.

Within GIRLS, she serves as a teacher and mentor, specifically guiding the newcomer trio of Agira, Miclas, and Windom. She operates at her own pace regardless of circumstances, balancing leadership with an idol-type presence. A dedicated novel chapter in the web series accompanying the anime's second season confirms her expanded media presence. The available information does not detail her involvement in other official extensions such as the movie "Kaiju Girls Black".