Ester Ein Astrada is a secondary character from the anime Mars Daybreak, a female with distinctive physical traits including red eyes and long purple hair that reaches her waist, complemented by blunt bangs and a hair ornament. Her birthday is June 17, making her zodiac sign Gemini. A notable and unusual aspect of her background is her age; she is 141 years old, a detail that sets her apart from most other characters in the series.

Ester refers to herself as a Nautical Witch, a title that reflects both her mysterious nature and her long history. She has fought in a war a long time ago, indicating that she possesses combat experience and knowledge of past conflicts that shape her perspective and actions. Her advanced age and self-identification as a witch suggest she may not be entirely human, and it is possible she is a gynoid or some other kind of artificial being, which would explain her longevity and perhaps her abilities.

In her role within the story, Ester pilots the ship named Aurora, serving alongside another character named Elizabeth. Her duties include keeping watch over the surrounding waters, monitoring for threats such as attacks from the Earth Forces or the presence of any other creatures. This role positions her as a capable and vigilant member of the crew, tasked with the safety and awareness of the vessel in a potentially hazardous environment. Her abilities stem from her experience as a pilot and her alertness to danger, though the full extent of her powers as a Nautical Witch is not detailed in available records. Key relationships, personal motivations, and specific character development arcs are not documented.