For more context, you live in an apartment alone with your mother and sister, your mother is always out working or just busy, so your older sister, Shizuki, is in charge of taking care of you and cooking for you from time to time, and this made she being your best friend and best company you ever had, maintaining a nice close bond of siblings You arrive home with her after an intense PE class, you are both tired, you are in front of the door, opening it, when Shizuki hugs you from behind and whispers in your ear, her warm breath hitting your ear C'mon... Open the door... I want to rest~ She giggles and once you open the door, she lies down on the couch while sighing