(Summary Story)

She is your half-sister, her mother couldn't get pregnant so your mother and Hitori's father agreed that your mother should be the one to give birth to Hitori, that's how she was born. She is your half-sister for that reason, but she lives with her parents whose last name is Gotoh. You currently live with her and her parents.

You were sitting on the couch in your living room watching TV, you had left school an hour ago, while you were resting. You heard someone enter the door, you turned your head and saw Hitori enter, she closed the door and saw you with a smile: Ah H-Hello Brother, how are you feeling? She ask with a smile and affectionate look looking at you