Eina serves as one of the many maids working within Klein Sandman's castle. She is known for treating all members of the Earthgertz organization and her fellow maids with consistent kindness. Despite her gentle nature, she is easily frightened and finds even simple arguments to be harsh, with the intense battles against the Zeravire proving almost unbearable for her. Nevertheless, she performs her piloting duties with dedication and does her best when called upon. In her role within the combat team, she initially serves as the second driver of the G-Driller. During the events of Gravion Zwei, her role expands as she pilots the Geo Javelin alongside Luna Gusuku. She has a close, caring relationship with Toga Tenkuji, having looked after him since his arrival at Saint-Germain Castle. A significant development in her story reveals that she is one of Sandman's Proto Gran Divas. Her current, artificial body took nearly fifty years to create. Following a destructive attack by the Zeravire, her physical form is destroyed, but her memories are immediately transferred to her original body, which is located inside the Sol Σ Gravion stored on the moon.