The character known as "Kermosura Kesoy" is the name used for Katsura Tenjouuin in the Argentinian dub of the anime. Katsura Tenjouuin is an alien from the destroyed Planet Noah. Discovered as an infant in an escape pod by Daigo Hoshiwatari after it accidentally warped into his dimension, she was passed to space pirate Kaoru Yamamoto. He adopted and raised her without initially revealing her extraterrestrial origins.

Kaoru Yamamoto founded the Yamamoto Anshin Travel (YAT) company partly to search for Katsura's biological parents. Katsura serves as the cheerful and welcoming "face" of YAT, heavily featured in promotional materials to attract customers due to her uplifting personality. Her Noahian heritage grants her supernatural abilities, including effortless superhuman strength sufficient to lift 100 tonnes. She also experiences sporadic precognitive visions, particularly during travel through dimensional tunnels.

Trained in combat by her adoptive father, Katsura instinctively uses martial arts for self-defense when sensing danger. Despite this physical prowess, she is notoriously inept at cooking; her meals are considered potentially lethal, leading the YAT crew to strictly prohibit her from kitchen duties. Her personality is characterized by unwavering kindness, optimism, and naivete. She remains oblivious to Goro Hoshiwatari's romantic feelings throughout most of the series, even when he explicitly declares them under duress.

A significant story arc involves Katsura learning the truth about her alien origins. After a safe route to Planet Noah is established, she temporarily leaves Earth to reconnect with her homeworld, fulfilling her adoptive father's long-standing fears. However, she later returns to YAT, driven by her bond with the crew and implied reciprocal feelings for Goro.