Ruki is the type of person who, in the beginning, sees Digimon as nothing more than mere computer data. She aspires for her partner, Renamon, to become the strongest Digimon ever. Eventually, she realizes that the two must be on equal partnership and friendship. She is a bit bitter and slightly antisocial thanks to her parents' divorce, but Takato, Jenrya and Renamon, manage to bring out the best in her, by showing her (among other things) that friendship is priceless.
Ruki's relationship with Renamon is unusual (due to Renamon being the most mature of rookie Digimon), they talk as equal than either a pet or a playful child. Ruki's proud, independent, grouchy and cynical personality is substantially different from most of the female characters in the series, pretty much a typical teenage rebel.
****** POSSIBLE SPOILER - Character development ******
Her personality is due to her parents divorcing, she was closer to her dad, and her mum doesn't really understand her, always pushing the tom boyish Ruki to try and be a model. This left Riku feeling isolated and forced her to be defensive and rebel. As a self defense mechanism mentally, she believes she "doesn't need anyone". Which I believe also accounts for the way she at first treats her digimon.
Deep down Ruki is loving and caring, wishes to protect her friends as well as the city. even though she puts on a "defensive act", being tom boyish is a genuine part of her personality.
Vova
