A week of tsundere living together with the unfriendly busty lady next door

My neighbor's JULIA sister has always been unfriendly, cold and scary, so I'm a little unpleasant... But we were close friends with each other, and our parents ended up taking care of me for a week on our trip! Despite her blunt attitude, she's a slutty older sister who somehow makes me slut! He watched my AV without permission, called me to the SM club where I worked part-time...and then suddenly he realized this. Sister, actually, about me...? Experience a life of living together with a tsundere busty childhood friend who is completely subjective!