Touka family?. DO NOT READ INLESS YOU'VE WATCH THE WHOLE SEASON 2!!!!

So dose anyone know what's up with Touka brother?. like why dose he hate her?. to what I see it seems like they were the best of buddy's. and why dose he hate touka so much. I'm dying to know. and what happen to there dad. I mean I know he died but how?. and what about there mom?. I thought for sure it would give us a background of her mother. I thought since they gave a background on yoshimura the owner of the coffee shop. being the owl they would give uss a bigger background of it. but there's still a change that they might give one in season 3.