Looking for a manga

Does anyone know a manga where a girl gets a new step brothers. (not brothers conflict) I forget how many of them there are but she ends up getting attacked and has to pull a knife out to defend her self and the brothers come in and beat the shit out of everyone. she ends up having a break down at home and they think she will hurt her self and a girl she wasnt friends with ends up calming her down. i think it was still ongoing but not too sure