My Evil Stepbrother

As the daughter of a mom who is always working, Reno lives a lonely life. She's so afraid of being left alone that she self-isolates to prevent anyone from leaving her. But when her mom suddenly remarries, she gains an older stepbrother, Ryo. All Reno wants is a family, but all Ryo wants is to hang out with his friends. Can this pair work out their differences?

(From Mangamo)