Is there any more info on Ruuri like her hobbies and/or favourite foods?
you can read it from japanese wikipedia
Her hobbies are visiting (shinto?) shrines and playing with her cat "Ruki-kun".
Her favorite food is... I don't know. I think her favorite food has been mentioned in the show but I forgot.
But she (and her families) hates coffee, spicy foods, and wasabi.