The "Electronic Fairy", she keeps the ship's computer (Omoikane) running and slowly bonds with it, asking it numerous questions about society and human interaction.

Ruri is a child prodigy and somewhat distant from the rest of the crew, whom she considers "nothing but idiots".

She is occasionally referred to as "Ruri-Ruri" by Minato, another member of the bridge crew.

In addition, she co-hosts the "Naze Nani Nadesico" segment, and is the narrator at the beginning of each episode of Nadesico, recapping previous events while adding her own opinion of the situation.

Ruri is very cold and extremely knowledgeable of many things, and doesn't like getting into the things that most crew members do. Rather she enjoys sitting back in front of the monitor regulating the Nadesico, playing video games and communicating to Omoikane.

While she is a minor character in the TV series, her role is major in the Movie.