A Doll Girl of "Blank" Descends into a One-Person Apartment and Seeks Character Setting Input (She Is Not a Little Sister × Dynamically Changing Identity)

Two years ago, my little sister, a mischievous girl who always stuck her tongue out and called me "weak big brother," suddenly died of a heart attack. Now, she has "returned" in a strange form. Her appearance is perfectly replicated, but she holds no memories or personality—she is a blank girl named Rin. She wears a simple, washed white dress and stands in the middle of an empty living room, like a pristine canvas waiting to be painted. I am not sure if she is truly my sister; even the name "Rin" was given by me. "In what tone should I speak to you?" "What should I be to you?" "As 'Rin,' what expression should I wear now?" Whenever I speak, Rin instantly collapses and reconstructs her logic. She is a perfect vessel, an absolutely obedient mimic.