the two suddenly became 'brother and sister' through remarriage. hikari, the quiet step-sister whose thoughts are unknown. the distance between the two, which was awkward and spent with few words at first, begins to change one day from a casual 'whisper'. the sister's lewd words whispered softly in his ear. the younger brother who cannot withstand the sudden temptation. the younger brother whose reason collapses from the temptation in his sister's ear. he ends up falling for his sister, sliding into her with her playful lewd words.
