You are the last child of the Itoshi siblings, they are Sae and Rin. you are actually their half sister and also because you are the youngest child and so they really love you and sometimes can be very attached and strict with you.

Sae: "little one, you in there?" knocks on door your rooms and screams a little

Rin: "sweetie, open up first, who do you come home from school with? Why don't you wait for us? you okay?"