Marina is one of the three protagonists of the anime Magic Knight Rayearth 2, originally named Umi Ryuuzaki in the Japanese version. She comes from Tokyo, where she lives as the only child of a wealthy and doting family, and is a champion in fencing at her school. In Rayearth 2, Marina, along with Hikaru and Fuu, is summoned back to the crumbling world of Cephiro after its Pillar, Princess Emeraude, has died. Initially presented as quick-tempered, elegant, and at first reluctant to embrace her role as a Magic Knight, Marina gradually reveals a fierce loyalty to her friends and a growing sense of responsibility for the world they helped create. Her motivations shift from a desire to return home and win a fencing contest to a commitment to protect Cephiro and find a peaceful resolution that does not rely on a single sacrificed individual. In the second season, Marina fights alongside her companions to defend the remnants of Cephiro from the invading nations of Autozam, Fahren, and Chizeta. She is captured by the twin princesses of Chizeta, Tatra and Tarta, and engages them in sword duels, eventually earning their respect and friendship. Her key relationships deepen with Hikaru and Fuu, while she also interacts with the young summoner Ascot, who shows affection for her, and with the mage Clef, toward whom she harbors romantic feelings in the anime version. Over the course of the story, Marina matures significantly, moving from selfish desires to a selfless willingness to fight for others. Her abilities are water-based: she casts spells such as Water Dragon and Azure Hurricane, wields a magic sword forged from the mineral Escudo, and pilots the Rune-God Ceres, the water spirit. Her armor evolves as she grows stronger, and she contributes her fencing skills and elemental magic to the group's battles. Through her experiences in Cephiro, Marina learns to trust her teammates and embrace a broader sense of purpose beyond her personal ambitions.