My neighbor's sister, Shion, has always been unfriendly, cold, and scary, so I'm not good at it... However, my parents are on good terms, and they decided to take care of me for a week while my parents went on a trip! Contrary to her blunt attitude, this older sister spoils me for some reason and comes to me as a slut! Watching my AV together, calling me to the SM club where I work part-time... and suddenly I notice. Sister, are you really talking about me...? Cohabitation life with a tsundere big sister to experience completely subjectively!