As the oldest sister and leader of the Red Snappers, Rouge commands the elite all-female team representing the NESS faction. Her name, derived from the French word for "red," reflects the team's colorful theme. She pilots the specialized Red Snapper Superior spacecraft, equipped with the powerful Ultimate Impulse Cannon, rivaling Yohko Yamamoto's Everblack Cannon. Rouge excels as a pilot, radiating immense pride in her team's strength. This pride occasionally manifests recklessly, such as removing her spacecraft's automatic teleportation module—a safety device designed to save pilots before destruction.

Her fierce rivalry with Yohko Yamamoto extends beyond starship combat, fueled by their competition for the affections of NESS officer Fluger. Rouge feels deeply indebted to Fluger for past aid to her family, intensifying her drive to prove herself. This rivalry escalates when the Red Snappers become trapped within the anomalous cosmic object known as the "Boiled Egg." Inside, Rouge encounters an artifact that absorbs her, forcing her to relive Yohko's memories and uncover her secret origin as a recruit from 20th-century Earth. Armed with this knowledge, Rouge challenges Yohko to a high-stakes duel, demanding Yohko permanently return to her original time if defeated.

The duel remains unresolved due to an emergency malfunction at their battleground space station. Rouge instead proposes a decisive foot race, which Yohko wins. Rather than fueling further animosity, this shared experience shifts their dynamic toward mutual respect. They transition from bitter adversaries to acknowledged rivals, recognizing each other's formidable skills and tenacity while maintaining their underlying competitive spirit.