Lives in a really nice traditional japanese home with her easygoing, chat room stalker grandmother and her uptight, self absorbed, overly sensitive mother. No father is to be seen as of yet, which would make her the only tamer so far with a single parent.
Her mother, who is a model, is constantly pressing Ruki to become a model herself . Because of the pressure her mother is constantly putting on her Ruki develops a tomboyish nature and a hurt you before you can hurt me attitude, however, exposure to the other tamers softens her up and she becomes more open. (To bad)
In the beginning of the show the other tamers have a hard time communicating with her because both she and Renamon are more likely to try to kill whoever is trying to talk to them than anything else. Eventually she admits to Renamon that she does care about her well being and about others, and stops trying to maim/kill anyone within a ten meter radius. After she offers to teach Juri how to play the digimon TCG she opens up even more and after Juri is partnered with Leomon they become friends and are often seen together.
After winning a tournament Ruki receives a digivice, convinced she is dreaming Ruki decides that she might as well make a wish and she asks for a really strong digimon. And she get Renamon and with her new partner begins killing every digimon that appears. Even though the two are a virtually unbeatable team, Renamon doesn't digivolve until Ruki changes her goals a bit.
Renamon is quiet, powerful, loyal, and protective. Somehow she weathered the period of time when Ruki tried her hardest to convince herself that Renamon was nothing but meaningless data, but once Ruki changed they became an even better team and for the first time had a friendship on both ends.
If there are any two digimon any more alike than Leomon and Renamon I have yet to see them. They act the same, talk the same, fight in the same style, little is known about both of their pasts. If one really thinks about it Ruki and Juri are very alike also.