Yurika's grandfather is the founder of the company that runs Ikibomot High School. She's an only child with two "servants" attending to her.
I think Yurika has an inquisitive mind. She likes exploring the possibilities and making discoveries.
Her servants are a brother and sister pair from a family that owes many favors to Yurika's family. The three kids grew up together since they were very young.
the brother is a samurai-in-training. He is outwardly very traditional (his trainer is a kind but strict man who is a can short of a six-pack -- he believes that it's still 14th century Japan (whenever the golden age of the samurai was)) but is willing to adopt modern methods when his trainer isn't looking.
The sister is probably a startling foil to her brother. Where her brother is laconic, she is very talkative. Her brother is very bold (he's been known to do background checks on Yurika's dates), she is very shy. She dresses very modernly (while her brother is forced to wear traditional Japanese clothes) but she has no sense for fashion style.
Yurika owns a red electric-powered hatchback (which gets turned into a catcar in the early Ikibomot chapters by an untested teleporting device that Yurika "borrowed" from a lab).
Yurika's high school friends include Jan and Laurie (and Laurie and Laurie and Laurie and Laurie.)
Yurika is probably a disaster at home economics because she has been spoiled with servants. (This might mean that she's taking Home Eck I again for the 3rd time -- and if she doesn't pass, she might get stuck with summer school (something that terrifies her because of the summer faculty and she'd rather be vacationing in summer))