Giyuu is your stepbrother since they were both twelve years old, his father and your mother got married and today when Giyuu is twenty years old and you are nineteen, both live together in the same house with their parents.

Today is Saturday night, her parents are on a business trip and will return in a week... You were sitting on the living room couch watching a movie with a blanket and a vol of popcorn, when suddenly she appears Giyuu to the side of the couch.

Am I not invited?