Carmen 99 (real name, Carol Mendosa) is a bright and self-sufficient intelligence agent/mercenary who Van and Wendy encounter in the second episode of the anime, although Van apparently has met her before. The nickname 'Carmen 99', comes both from her bust measurement (99 cm) and the number of hidden accessories she always carries. She is often looking for more ways to earn money.
Carmen grew up in the town of Trinolia with her uncle and his daughter (having lost her parents), both of whom she shared a close friendship with until she left the town. Throughout the series, Carmen frequently leaves Van and Wendy's company to later reunite with them, until she finally joins forces with them at the final stand to save the planet.
In the second to the last episode, she infiltrates the Clawed Man's headquarters along with Yukiko, planting bombs along the way. Carmen winds up in a room filled with the flowers that devastated her hometown, where she confronts Fasalina, her nemesis, for the last time. While they fight, Carmen admits to being jealous of Fasalina's directness, freedom and innocent appearance, but declares that she would rather die than become like her. When the Clawed Man dies, Fasalina begs Carmen to kill her. At first, Carmen is more than happy to do so, but when she finds Michael Garret running towards Fasalina, she spares both of them.
In the end, she also admits to liking Van very much after he finally remembers her name, though she laughs it off, knowing that it wouldn't work between them.