Lou Roux is one of the operators of the Cosmo Base, later, after it was destroyed by a Mimetic Beast she is sent to Earth by her father to protect her. She later helps Ken recover from his injuries and joins him in his renegade fight against the Mimetic Beasts.
During the beginning of Shinkon Gattai Godannar, Lou is in Cosmo Base monitoring global activity with her father and the rest of the base's staff. She plays a relatively minor role during the first four episodes of the first season, acting as a coordinator of the robot pilots' battles against the Mimetic Beasts. On Episode 5, when Lou's uncle, Hal, comes in via a shuttle to relieve Lowe and his crew, a Mimetic Beast, hidden in a secluded area of Cosmo Base, suddenly attacks by unleashing a blast through the base, cutting Hal's shuttle in half and killing him instantly. The entire Cosmo Base escape on emergency evacuation pods, but Lou and her father instead escape on the Cosmo Diver. The Beast bursts through the structure of the space station, endangering the escape pods, and Lowe engages it in combat to protect the evacuees. At the same time, he detaches Lou's Cosmo Diver unit and sends it on auto-pilot to Earth, against his daughter's wishes. Lou is then found by the Dannar Base, and, after a rocky introduction and emotional breakdown, Lou is taken in by the Saruwataris, however, she acts rather cold and distant towards them most of the time. When Lou returns to Cosmo Base, assisted by Goh, she discovers that her father had died, and the monster that killed him is still alive, she manages to kill it and prevent the falling debris of Cosmo Base from crashing into Earth to do irreparable damage, but the revelation of her only parent's death puts her in a state of constant depression, and an obsession for revenge. Much later, she encounters Ken and nurses him back to health, upon discovering he is a robot pilot, she asks him to secretly tutor her on how to pilot them.
When the series begins, Lou is a happy and mostly normal young girl characteristic of her age and shows a very close familial bond with her father, perhaps the result of having lived together for a long time in Cosmo Base; however, her youth belies a mature intellect. After the destruction of Cosmo Base and her father's subsequent demise, Lou's personality changes considerably, the immense trauma carried by those events had shattered her to the core, becoming taciturn and emotionally distant to her surrogate family, the Saruwataris and the staff of Dannar Base, and becoming obsessed with revenge. In spite of this, they all tried their best to befriend her and to help her forget about the tragedy that befell her, ignoring her attempts to convince them to teach her how to pilot. Unfortunately, their ignorance to the issue would later prove to be their folly.
After Ken mysteriously appears before her with heavy wounds, Lou befriends him and nurses him back to health in secret.