[Manaita Koujou (Miginer)] Imouto-chan wa Arawaretai!! 3

A drowsy little sister is caught off guard when her bespectacled big brother tiptoes up the stairs and into her room at night, finally granting her wish to be washed. Stripped bare and blushing in the bath, she has him tie up her hair before insistently scrubbing him down herself—until her small hands discover something hard and stiff, like there are bones in it, that she remembers seeing in his comic books. What begins as innocent bathing curiosity leaves the adorable girl with her soft lips wrapped around her brother, a thorough cleaning that never needs to go any further.