recently my sister is unusual

recently my sister is unusual
i watched the anime the anime is good but the plot remains stilll a mystery i mean to say the ending is bullshit no conclusion at all she just goes back at being like her ususal . and the mc doesnnt lust over his sister he is not a siscon so i dont know what is the meaning of this anime . the angel (the route is fckued up they didnt even tell who she was but that milk lady dont know her name can see them . and sometimes mc also but they dont know her. so that means she is a stalker and when she died she takes the body of his step sister to enjoy herself why would the step sister will help because she is makeing the life of step sister hell . ) this anime ecchiness is good still being a pg-13 anime it showed significant amount of fan service and i loved it from the side of ecchiness it's great not gonna lie but from the perspective of a plot enjoyer its dulll . will give it a 7/10 because of its ecchiness