She's the semi-famous daughter who was following in her super famous mother's footsteps...and he's her younger, untalented (classical talents anyway) brother, who probably didn't get too much attention from their mother before she died. There's a good chance he's a little resentful. He's also of the age where teenage boys get rebellious, especially if they lack a father figure and live with their grandmother.Originally Posted by MFauli
As for why there's no proper RideBack club where he goes to school, remember that these are more expensive versions of sport motorcycles. Did you know anyone who owned a street bike when you were in the last years of high school? I knew two in a school of ~3000 at legal driving age. Most people Rin's brother's age can't afford something that expensive. It also looks like they cost a lot of time and money to maintain, more like helicopters or racing bikes than a normal street bike.
Except for Tamayo's and Okakura's, the RideBacks used by the club are communal. Rin gets to use Fuego more exclusively because she's the only one who can actually keep it upright.