Now that I think about it, it reminds me of Bokura wa minna Kawaisou, with the high school student moving to a boarding house and meeting a girl going to the same high school, the unkept older guy, the big breasted older woman and an elderly landlord. Although Bokura wa minna kawaisou doesn't have SM stuff. ^^ (Except maybe neglect play since she frequently gives him the cold shoulder haha)